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Rechargeable battery charging time vs. mA current calculator

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NiMH & NiCd rechargeable batteries charging time – mAh – mA / hours :

Step 1: Enter a mAh capacity of your Rechargeable Battery

* Enter a mAhr capacity value as shown on one battery only (to charge 1 to 4 batteries at once.)
* Precision in results is how many numbers after decimal point (0 – 9)

Enter a mAh number of your battery : (ei: 2400) mAh   –   Precision :

Step 2: Select a rechargeable battery size/type to calculate from

Step 3: Select battery charger mA current output rate for time length


Battery size, charging time length, charger current output type.

How long time does it take to recharge a rechargeable battery?

Formula for calculating batteries charging time :

hr = mAh / mA

hours” equal “battery size in milliampere-hour” divided by “charger output power in milliamperes

(Need more information? The charge formula is explained in details with examples further below.)

Charging rechargeable batteries.

Type into the calculator your rechargeable battery’s capacity number, normally can be red on the battery body e.g. 1700 mAh ( milli-ampere-hours ). Then select the battery type/size in the left column ( NiMH – NiCd – AAA – AA – C – D – 9V ( 9 volt )) and in the right side select a current output ( electric power output ) of your charger in mA ( milli-amperes ).

Type in a capacity number of one battery only. Without changing outcome as per hours/mA a 1-4 batteries can be charged.

You can select and use a specific / special battery sizes at the bottom of the field and then set a different current output from a battery charger, if needed, by choosing the 1mA current and multiplying the outcome backwards – dividing in fact by the existing current value at which your charging equipment operates.

Re-charging 9 volt rechargeable batteries

Time control for charging of common 9V rechargeable batteries ( NiCd and NiMH 9 V batteries.) The timer takes longer because these can only be charged at much lower current rate of 0.1C or 1/10C ( mAhr/10 = charging time in hours ) of their mAh capacity value. Usually between 30 mA to 100 mA depending on the 9V battery capacity in mAh. This is still great to put up with considering that the 9 volts non rechargeable batteries cost arm and leg, but they don’t have to.

Trickle charge, continuous charging method

This is done with a very low charging current to keep the battery or batteries constantly alive, same like with a cordless phone battery pack that is docked in its station base.

Lets do the life/live charging examples, but before still in a short theory to clear some practical terminology out from the way.

Common abbreviations – symbols – prefixes

The International acronyms one will possibly come across with while using batteries and their changers:

How do I calculate charging time for rechargeable battery manually ?

Formula for manual calculation for battery recharging processes

AAA – AA – C – D sizes rechargeable batteries:
hours ( charging time ) equals to 12 x Ahr = hrs OR 12/1000 x mAh = hrs
( 12/1000 x mAh = hours of charging )

Example calculations with this manual formula; calculate charging time length for 2400 mAh NiMH AA size 1.2v rechargeable batteries with 100 mA charger and secondly with a 3.5 times more powerful 350 mA current output power charger:

100mA battery charger:
12 : 1000 = 0.012
0.012 x 2400 = 28.8 (hrs)

It requires 28.8 hours ( 28 hours and 48 minutes ) to charge or recharge aa size 2400mAh batteries with charger that has 100mA current output.

350mA battery charger:
12 : 1000 = 0.012
0.012 x 2400 = 28.8
28.8 : 3.5 = 8.2 (hrs)

It takes 8.2 hours ( 8 hours and 12 minutes ) time to charge or recharge 2400mAh batteries with charger that has 350mA current output.

Here is a second example of how long to charge batteries but this time for charging 1800 mAh 1.2 volt NiMH aa type rechargeable batteries and with the same current chargers:

100mA battery charger:
12 : 1000 = 0.012
0.012 x 1800 = 21.6 (hrs)

It takes 21.6 hours ( 21 hours and 36 minutes ) to charge or recharge aa size 1800mAh batteries with charger that has 100mA current output.

350mA battery charger:
12 : 1000 = 0.012
0.012 x 1800 = 21.6
21.6 : 3.5 = 6.2 (hrs)

In total 6.2 hours ( 6 hours and 12 minutes ) is needed to charge or recharge 1800mAh batteries with charger that has 350mA current output power.

9v ( 9 volt ) rechargeable batteries:
hours equal to battery mAhr/10 ( mAh/10 = hrs )


battery charging time = capacity of the battery / charging current power output of the charger

hr = mAh / mA

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How to charge rechargeable batteries? Calculate the time for how long it takes to fully recharge a battery with a specific current output battery chargers.

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  1. This is great! I was looking for how to recharge aaa and aa size rechargeable batteries. Our very old charger died recently so I build provisionally a manual charger powered from a car battery, its current is 200 mA , I can connect this charger in the morning and switch off after work day. The batteries, 15 to 20 of them, 1.2V we use in remotes, mini maglite flashlights, 2 larger maglites, and etc. handy for around the house, all are very old, years old!

    Battery type : 1600 mAh NiMH size AA rechargeable battery

    Require : 9.6 hours of re-charging in 200 mA current output charger

    Fraction : 9 3/5 hours of recharging at 200 mA current battery charger

    Size AAA 170 mah 1.25V batteries ( 1.25 volt not 1.2 V ), can’t see any more on these whether they are nicd or nimh. But they still hold power perfectly even though I never discharged them before charging; only they are always pretty flat before they are placed into any charger:

    Battery type : 170 mAh NiMH/NiCd size AAA rechargeable battery,
    Require : 1.0 hour of re-charging in 200 mA current output charger … that’s pretty right it took this long also in my old inteligent battery charger.

    Comment from/about : aa and aaa battery charger | Permalink

  2. I have 4 x 1750 mAhr ( milliampere hour ) each NiMH AA rechargable batteries and also using a simple-manual switch off with no timer built in 500 mA universal battery charger.

    battery type : 1750 mAh NiMH size AA rechargeable battery,
    time = 4.2 hours to be fully recharged with 500 mA battery charger,
    fraction : 4 1/5 hour(s) to be fully charged by using 500 mA charger electric power current.

    Comment from/about : 1750mah nimh aa cells and 500ma battery charger | Permalink

  3. I’ve been using 2 x size AA 2400 mAh and 4 x 2700 mAh capacity size AA batteries and can set my NiMH / NiCd battery chargers at up to 450 mA current output power. Usually I just recharge them when my radio, mini led light and large maglite, flashlight are flat. Meaning I never run discharge before charging as the batteries should be equal and are also charged in the same groups as they are being used. This is very practical calculator.

    Cell type 2400 mAh NiMH size AA rechargeable battery

    needs 6.4 hour(s) of re-charging in 450 mA current output charger

    fraction – 6 2/5 hours of re-charging in 450 mA current output charge

    Cell type 2700 mAh NiMH size AA rechargeble battery

    needs 7.2 hour(s) of re-charging in 450 mA current output charger

    fraction – 7 1/5 hours of re-charging in 450 mA current output charger

    Battery type : 5000 mAh NiMH size D rechargeable battery,
    require : 14.5 hours of recharging with 450 mA current output charger,
    fraction : 14 1/2 hour(s) of recharging with 450 mA current output charger.

    Comment from/about : how long to charge 2400 mah AA size battery | Permalink

  4. Yesterday I was finding out how long does it take to recharge a aa battery. I am using a travel sort 350 ma 1.4V volt battery charger for 4x ni-mh AA type 2100 mah size batteries and, as it seems they have charged properly with the timing below.

    Battery type : 2100 mAh NiMH size AA rechargeable battery.
    Require time : 7.20 hour(s) of re-charging in 350 mA current output charger.
    Fraction outcome : 7 1/5 hour(s) of re-charging in 350 mA current output charger.

    The same charger charges 4x triple aaa size batteries at 150 ma power current and 9V type batteries at 30 ma output. I can say that I am quite happy about it; saving lots of money per each year, and the environment, instead of buying many alkaline non-rechargeable 1.5V batteries for personal and at home use. Thank you for this mAhr / mA versus charging time length battery calculator.

    Comment from/about : aa size nimh battery charging with 350ma charger | Permalink

  5. How long to charge 2700mah batteries with 150ma charger? I need locate somewhere a more powerful electric transformer for my diode bridge to shorten this long charging time!

    Battery type : 2700 mAh NiMH size AA rechargeable battery,
    Require : 21.6 hours of re-charging in 150 mA current output charger,
    Fraction : 21 3/5 hour for full recharging in 150 mA current power output charger.

    Comment from/about : nimh rechargeable batteries 2700 mah in 150 ma charger | Permalink

  6. My charging time calculation of aaa nimh battery for remote controls around the house and type d large rechargeable batteries used in maglites and maglite flashlights I have. I was wondering whether it is all right or safe to be recharging 9 volts batteries for fire alarms?

    Battery type 1100 mAh NiMH size AAA rechargeable battery,
    take 7.3 hours long time to be fully recharged with a 180 mA charger.
    Fraction : 7 3/10 hour to be fully recharged with charger with 180mA current power output.

    Battery type 4700 mAh NiMH size D rechargeable battery,
    take 11.1 hours time of re-charging in a 550 mA current output charger.
    Fraction : 11 1/10 hour of recharging in 550mA current power output charger.

    Comment from/about : charging time calculation of battery | Permalink

  7. Before I found this charging calculator I was facing the dilemma about how long does it take to recharge a aa battery, or, how long do aaa rechargeable batteries take to charge. So basically now I know how to set for any size of battery charging time and also how to choose the right power output, how long does it take till the batery charging process must be turned off to stop, and, a battery charger calculation.

    Comment from/about : How long to charge rechargeable batteries for. | Permalink

  8. I used this page to calculate recharge-able batteries charge time, specifically so charge time for 1.2 v 1100mah ni-mh and other 1.2volt aaa mah values rechargeable batteries, plus how long to charge 9volt battery for replacement in firealarm which I test on regular bases.

    Comment from/about : How to calculate rechargable batteries charging time. | Permalink

  9. This is perfect device to calculate charge time for ni-mh rechargeable aa ( and type aaa ) batteries for me and, was wondering what would be the time taken for aa rechargable batteries for charging in my 5 hour time preset 380ma strong charger, whether the timer limit should be enough or if not if I should double it – which is the case.

    Comment from/about : charging time for rechargeable aaa and aa battery | Permalink

  10. I was looking for c code meaning or c symbol and how to use it in battery charging processes. I wanted to make sure that the C letter stands for the total capacity of the battery in mah milli-ampere hours – to be able to calculate manually how long does it take to charge a mah battery, with a question; how many hours do i charge a aa rechargeable battery?, but this calculator does it perfectly enough without having have to use pen and paper. Thank you, keep up doing the great work.

    Comment from/about : battery charging c code meaning or c symbol | Permalink

  11. … how long 4 aaa and also aa nimh charge for 1800 mah etc. plus charge rate ma calculate for choosing an appropriate charger, having one 300 milliampere transformer to use.

    Battery type 1800 mAh NiMH size AA rechargeable battery,
    takes 7.2 hours to be fully recharged with using 300 mA charger.
    Fraction number 7 1/5 hour-s to be fully recharged in 300 mA battery charger.

    Comment from/about : charging rate ma calculate | Permalink

  12. Any effect if I use 2 x 1600mah together with 2x 2800mah rechargeble GP batteries?

    Comment from/about : Use 1600mah together with 2800mah Nimh | Permalink

  13. charging time aaa

    Quick to calculate nimh charge current power with charging time for aaa batteries involved.

    Comment from/about : charging time aaa | Permalink

  14. Excellent! I also needed calculation or a charger table with how many hours it takes to charge rechargeable batteries.

    Comment from/about : how many hours charge rechargeable batteries | Permalink

  15. Thanks for this rechargeable aa calculator. I looked for this info to know how long time to leave my old battery in an old charge we have at home. I found out had to double the time from what I practiced before. Now I’ve been using the battery for actually a couple or three of days more, which already is two days extra of it being used, like before, only longer! I believe the charging process taken this last time had to be much more accurate.

    Comment from/about : rechargable aa calculator information | Permalink

  16. Great into for how to recharge battery DIY. Hat down for this tool!

    Comment from/about : how to recharge battery | Permalink

  17. Rechargeable batteries charging time; Is 9-1/2 hours charging time = or enough for 2300mAhr NiMH battery type and with 300mA nimh battery charger?

    Battery type: 2300 mAh NiMH size AA rechargeable battery (2300mAh),
    Require: 9.2 hour(s) to be fully recharged with 300 mA charger,
    Fraction: 9 1/5 hours to be fully charged with 300 mA battery charger.

    Comment from/about : charging times for rechargeable batteries | Permalink

  18. How long to charge 1000mAh Ni-MH batteries size AAA with 500mA charger?

    Comment from/about : alas | Permalink

  19. Due to the existence of this charge current calculator there’s no need, in fact, for a manual charge current formula which I initially searched for! I’m making DIY my own manual battery charger using the formula for a charge current that I found on this page.

    Comment from/about : charge current formula | Permalink

  20. Gaining information on AA’s battery charging time, I require exact four by 2300 aa batteries charging timing with 500mA charger, I have the SANYO brand batteries.

    4x AA Battery type: 2300 mAh NiMH size AA rechargeable battery,
    Require: 5.5 hour(s) for AA battery charging time to be fully recharged with 500 mA charger.
    Fraction: 5 1/2 hours for aa battery charge time to be fully charged up with 500 Milli Ampere charger.

    Comment from/about : aa battery charging time | Permalink

  21. Hi,

    Thanks for your info, but I’m a bit confused on charging time.

    Should be simple. Calculating for a 2000mAh NiCd battery (several sub-C in series). Charger is 400mA. Is the charge time simply 2000/400=5hrs, or do I always factor of 120% for time? If so, it would be 6hrs.

    Your calculator shows 3.9 hrs. What am I missing.

    Comment from/about : Rich | Permalink

  22. Rich, that’s because when you compare nicd and nimh batteries, nicd take less time to be fully charged and, nicd type in general has also lower capacity. The chargers for nicd and nimh battery are slightly different too.

    Comment from/about : nicd and nimh batteries | Permalink

  23. I was wondering if there are any voltage restrictions to recharge the batteries since it only says the amps.

    Comment from/about : Volts? | Permalink

  24. If battery is fully charged at that specific time, what is the current value of a battery? I had set to 9 hours with 300mA charger power output current in past, and adjusting to 9.2 hours from now on to 9h plus 30min. Results are below:

    Battery type: 2300 mAh NiMH size AA rechargeable battery
    require 9.2 hour(s) to be fully recharged with 300 mA output current charger. Fraction: 9 1/5 hour(s) to be fully recharged with 300mA charger.

    Comment from/about : At what time is battery fully charged and at what current value? | Permalink

  25. Precise ma current to charging time for rechargeable batteries calculator. I made my own charger the other day and it works marvelous, hence help by the tool on this page to make it acurate.

    Comment from/about : Calculating mA current into charging time for rechargeable batteries. | Permalink

  26. It is handy to know about rechargeable batteries in detail. There are so many things in every house that operate on using batteries. Not just the flashlight, cameras, phones, nut some many more, even clocks which use batteries of several voltages or sizes. There are websites that offer discounts when buying batteries in bulk quantities.

    Comment from/about : Kenneth | Permalink

  27. Great Site. Thank You. Our Dirt Devil Mop Vac batteries went dead after several years. I purchased 6 new 1800mAH sub C NiCDs on e-bay to build a new battery pack for it. After I pushed the “Buy It Now” button, I was dreading that the charger wouldn’t charge these higher capacity batteries to full potential. Your site set my mind at ease and calculated about 9.3 hours at 150mAH charge. I then wondered if the batteries would be damaged by leaving the Vac plugged in all the time when not in use.(our SOP) Your trickle charge calculations lead me to believe that I am charging at 4-times that rate. Is it a hazard or will the batteries just give out in a short period of time? Thanks in advance for your response.

    Comment from/about : Damage from overcharging? | Permalink

  28. Couldn’t be better for battery charging time instructions for me!

    Comment from/about : Battery charging times. | Permalink

  29. This converter is excellent for quickly finding out how to calculate “battery-pack” charging time I use for my RC radio.

    Comment from/about : calculate “battery pack” charge time | Permalink

  30. […] charge to much less than given on the battery. also found a site to calculate the charging times Rechargeable battery charging time and mA current calculator | Convert to units measures. basics of calculating charging time is given on this […]

    Pingback from/about : Query on Sanyo batteries and Uniross charger – TechEnclave | Permalink

  31. Thanks for great article and tool,
    Please help,
    What is the exact time, i use 4 AA uniross batteries 2500mAH, with songle charger,
    It output is ‘DC2.4V 100mA (AA*4)

    Should i take output of charger as 100 or 400, please Answer.
    Will my charging time fast if i use only 2 batteries instead of 4 at a time.


    Comment from/about : Ashu | Permalink


    Comment from/about : can betteries be left in charg | Permalink

  33. For example by devision 2500/70~35
    Charging process will be same for 4 batteries or 2 batteries charged at the same time, 1 pair of batteries or 2 pairs together, in the charger giving same output to multiple batteries.

    Elsewhere or in different chargers structured (such as made on your own) can give e.g. to 4 batteries charged together needed 2*35=70 hours time to be fully charged.

    With most chargers it is clear that every pair of battery cells is placed in the charger in series for charging. Also, each pair gets same specific mA, as per your charger output used, when simultaneously charging 4 batteries/cells. Basically with one battery pair the charging current will also remain e.g. those 70 mA or your own specific. It is worth to mention that it’s advised to charge cells of the same mAh and to discharge all batteries prior the new charge so they all share the same capacity state, none will overcharge nor undercharge. Thanks cause this makes it quicker without calculating the time length with pencil on paper.

    Comment from/about : Process of charging rechargeable batteries at home, DIY easy way. | Permalink

  34. WE NEED THIS ITEM BEFORE 20/3/2010
    QTY ; 1
    Battery Charger Unit ( Longer ).
    Battery Charger Unit UP TO 450 A charging Current and to have these options for Normal Changing Processes, Fast Charging and Starting Options for the battery packs vs. the battery charger.

    Comment from/about : ENG : ADEL | Permalink

  35. Please help me about my 7.2 volt 6 cell nicad rechargeable battery pack for my rc. I am thinking of using a 15 v 700 ma charger for it but don’t know how long i should charge it? Also when i tried it once the pack became a bit warm to touch in only 1 1/2 hours. Please help thanks. If it helps i also have a 9volt 300 ma charger can you please advise me on this too? Like on the charging times thanks again.

    Comment from/about : Lennard | Permalink

  36. My cordless phone uses NiMH batteries 600AmH 1.2V. My question is, can I use charger with different specs, e.g. 1700AmH 9V?
    Your expert advice will be much appreciated.

    Comment from/about : Joe Silva | Permalink

  37. I am using the sony BC-CS2A charger to charge 27Ah soshine Ni Mh batteries. The charging led stops about after 2hrs. Is my battery not good or the charger. But when i remove the batteries after the led goes out & put back in the batteries the led goes on again. Does it mean i need to charge multiple times?

    Comment from/about : charging 2700ah ni mh soshine batteries | Permalink

  38. My phone came with a 3.6v 600 mAh battery. I ordered a replacement battery by part number but recieved a 3.6v 300mAh battery.
    Is it a problem to use it in the phone?


    Comment from/about : chilly | Permalink

  39. Sir,
    Today I purchased 10 numbers of KR2000SC for a project and I understand that this is in obsolescence.
    I am to use 5 cells for 6V and using a ten hour rating for charging my charger will be 200ma. What should be the voltage for charging 7V DC, 8VDC or 9V DC? I can change my smps to suit any voltage. I understand that the 5cells are to be connected in series. Correct? What is the harm if connected individually for charging using a 2V charger at 200 ma since the cell voltage is only 1.2V. Am I correct that the cells should not be discharged below 1V. Kindly advise at your earliest.

    best regards,


    Comment from/about : SHREERAMACHANDRAN | Permalink

  40. What is the exact time do I have to charge, I use 2 AA Camelion batteries 2700mAH, with Energizer charger NiMH-NICD twin selectable option
    The charger has output ‘ DC2.4V 100mA (AA*4)

    Thanks allot for your help

    Comment from/about : Camelion 2700mAH | Permalink

  41. The calculator is great however, does anyone know what the charging voltage should be from a solar panel to charge 3 D cell NiMH (3.6 VDC). (The solar panel has .73 A [no load] output)

    Comment from/about : Solar charging | Permalink

  42. I have a 8 cell battery out of a radio-control car, 1000mAh cell 9.6V. The charger is 250mAh. As this is made up of 1.2v AA cells, do I just select the NiCd AA and 250mAh on yr calculator = 3 hours? Maybe there should be a note on how to calculate multiple battery packs. What is the ideal voltage to charge a 9.6V battery? Thank you

    Comment from/about : Graham | Permalink

  43. […] battries – Good or not Not sure how long to charge your batteries? Use this cool tool here: Rechargeable battery charging time and mA current calculator | Convert to units and culinary measure… […]

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  44. We installed a battery room for 25kva Ups

    1) Battery capacity 1.2v , totally 75 numbers of battery
    2) charging current 13A
    3) charged voltage 78v
    4) total charging voltage 415v

    I want to know the charging time for the above , also if any detail

    Comment from/about : GOPIKRISHNA | Permalink

  45. I needed to know how to can calculate the electricity level of a charging-unit consumption for any battery charging process.

    Comment from/about : battery electricity consumption | Permalink

  46. Hi, please help me the charging time for a 2500 mah 4.8 Vdc nickel cadmium (4 cell battery pack).

    Comment from/about : Normal Time Charging | Permalink

  47. Wow — was jut looking for this — wanted to make a solar charger for my sanyo 2500mah batteries.

    Hope now my charger will be ready

    Comment from/about : Taprico | Permalink

  48. I am trying to use 8 AA 2600 Mah to power an RC model boat with no success. I charge the batteries in a store bought charger, but results are a disaster. I draw 1 amp and the batteries discharge in about 10 minutes. Is the 1 amp drain causing the problem?? For some reason the results form these batteries are very poor. These are a Tamiya product. Any advice would be welcome.

    Comment from/about : Nimh application | Permalink

  49. Hi. How do you charge these 8x Nimh AA 2600 mAh batteries, how are they actually connected to the charger and what’s its output? Give me all the numbers including the time of being charged. Have you tried charging them in 4x batteries’ lots? Sometimes also bad battery contact while charging can cause such problems, just an idea, there could be also a braking the circuit time out when you not watching, it’s common with my chargers so I clean the electric contacts from time to time.

    Comment from/about : Convert to | Permalink

  50. Battery chargers and charging methods for any battery type, battery charger power source and the technology is involved in my work schedule on daily bases. this calculators saves us a lots of time.

    Comment from/about : Thank you for this Battery Charge Time Calculator. | Permalink

  51. i sent you a really cool message but it got deleted by the captcha stuff.

    anyway, thanks for this excellent calculator.

    Comment from/about : Chris | Permalink

  52. I have for now dry Varta lead acid batteries and I need to know how to charge the battery for the first time due to its new state. And how to charge it consequently afterwards.

    Comment from/about : bader | Permalink

  53. is an excellent website with so many converters available. If you want to buy batteries or battery chargers you can shop for them online.

    Comment from/about : canon battery charger | Permalink

  54. I needed one clarification for battery discharge with the whole charge calculation, for higher end capacities battery e.g. 600Ah having both the supplies E.B. & D.G.
    1). Case one:- if E.B. stopped at the point of D.G., then the equipment connected to the battery has taken most power out, it is nearly fully discharged only remaining are some 2 hours for example.

    Now the continuous (trickle charging) takes effect, so I need to find out how much current will this system consume apart from the equipment load, if you have any easy calculation formula please let me know. Thank you heaps.

    Comment from/about : battery discharge to charge calculation | Permalink

  55. I search on the internet how to charge a rechargeable battery then I found this site. very hellpfull.

    2x Camelleon AA Rechargable bat @ 1500mah
    Eveready charger @ 170-200mah x 2 AA batteries

    = 9 hours or 10 hours fully charge?

    Comment from/about : Jedi | Permalink

  56. great grand helfull site. Thaks for all the usefull tech inforamtion regarding batteries

    Comment from/about : okhamza | Permalink

  57. I can’t get an answer for this. Can i charge a nickel-metal hydride 600mAh AAA/R3NM 1.2v battery in a charger with a input AC120v 60hz and a output DC2x (1.4v 100mA). The charger says it charges AAA R3 NiMH. But doesn’t say anything about voltage please help me thank you. The Charger is a Chateau Standard Charger

    added by Admin: I tried to look in chateaumanis to learn more about the R3NM brand battery but they do not have a contact there, unless I missed it somewhere?! The output of the charger is more important. 600 mAH batteries and 100 mA charger, I use also 1.4 Volt D.C output type charger. Otherwise rechargeable battery types 600 mAh NiMH size AAA take 6.5 hours charging with 100 mA charger. Do you know more about the R3NM batteries, what are they for?

    Comment from/about : Darrin | Permalink

  58. My cordless phone uses NiMH batteries 600AmH 1.2V. My question is, can I use my laptop charger with different specs, e.g. 1700AmH 9V?
    Your expert advice will be much appreciated.

    Comment from/about : laptop charger for cordless phone charging | Permalink

  59. I have 12V, 2.5Ah Absorbent Glass Mat Batteries. I need to know What is the Right Current to Charge it. As of now What is the Right Voltage & Amperes to charge it & How long Should it be Charged ?
    I have 12V 500mAh Charger. Is it possible to Charge it with this ? If yes, For how long will it Completely Charge it ? I dont have Multimeter !

    Comment from/about : Blue Ice | Permalink

  60. My old dear was given a camera. One of these little dige dodgi fancy new ones that don’t use film. We had some Energizer batteries, so to save the pension buying expensive AA’s, I thought I’d use them. First, they needed recharging. How long? I dunno. Found this site. Very helpful, even I can understand it. One small thing came up. When I went to check all the numbers for the sums above, on the bottom of the charger was a chart – which said….12 hours! Never mind! Me sums came out at 12 hours too. What we used to call Belt & Braces. (Two instant answers at once to same problem.)

    added by admin: Well done! Why would you buy a new batteries when those sitting around can be recharged again, 1000’s plus times. It also depends what is the capacity of the batteries but you’ve obviously looked it that already. Thank you for the nice note. I hope the filming goes great for you now! Let us know pls.

    Comment from/about : Poor old Pensioner | Permalink

  61. […] NiMH & NiCd rechargeable batteries charging time – mAh – mA – hours معلوم کیا جا سکتا ہے۔ ٹرائی کریں […]

    Pingback from/about : بیٹری معلومات چاہیے – پاکستان کی آواز – پاکستان کے فورمز | Permalink

  62. Photovoltaic solar panel modules.

    How about charging with solar generated electric power? The photovoltaic modules are commonly known as solar panel and are also used as components in large photovoltaic system to generate electrify.

    Trackback from/about : solar power electricity | Permalink

  63. Manual formula should be 12/1000 x mAh = hrs of charging.

    Added by admin: Yes of course thank you! 12/1000 x mAh = battery charging time in hours. I added plus + 4 instances on the page.

    Comment from/about : Manual formula | Permalink

  64. […] Rechargeable batteries charge times plus mA currents calculators. Rechargeable cells with various battery chargers are our specialty. We offer a huge selection of rechargeable batteries wholesale and in bulk, AA, AAA, C, D , 9 Volt and sub c cells. […]

    Pingback from/about : Battries nicad | Kimmelintl | Permalink

  65. Do you know why I can’t charge 2 aa batts in series, using a 6v 250 ma solar panel? On a dull day the 2 batteries larst 20 minutes only but on a sunny day I can get at least 5 hours out of the same long time of charging. I’ve also tried 2 x 4 volt solar panels connected together in parallel combination setting, trying to charge 2x 800 ma in series, and all batts are brand new. If I charge the batteries in a mains power charger then put them into my solar light then it will work all night. Any help please. Paul

    added by admin: Hi Paul, sounds like not enough power gets absorbed by the batteries from the solar charging. Did you use a volt meter to see the difference between the two; after the mains grid charge in comparison what’s it like after the solar charging? Let me know. First what I would do is; charge them for 3 days and without using the batteries, only after the last day charging how they perform. You can also measure these batteries every day to find out how the power in them steps up after each charge. Also, take them out from your solar charger when it’s not charging, it could also be discharging them in return.

    Comment from/about : cannot charge batteries | Permalink

  66. Is this result for 4x battery or for a single battery, will 4x batteries increase charging time?

    Comment from/about : nilesh | Permalink

  67. It’s quite difficult to understand for me, help me with; I have a battery charger on which the information given is like INPUT:220v 50Hz, and I have rechargeable battery of 2500mah, 1.2v which I bought new, so can you tell me how much of time in hours will it take for the first time recharge for 4 of these batteries at a time?

    Hi Miley, is there anything at the back of the battery charger that shows a number with mA behind the number? Let us know the mA value. Great 2500 mah batteries, I can see why you need to charge/recharge these properly.

    Comment from/about : miley – new 2500 mah battery charging time – process | Permalink

  68. Hi I’ve done what you have suggested with the following results:

    1st day 1.19v [flat]
    13 hour charge = 1.38V

    2nd day 1.42V 13 hour charge
    3rd day 1.43V 13 hours charge


    solar panel is a 6 volt 250mA fitted with dioad

    2 aa batts in series 800 mA

    With the mains charger 8 hours charged to 1.38 volts well its lasted 3.3 hours, so now I think there is a problem with the solar unit panel itself, the solar light consumes approx 120 mA unless you can think of anything else. Thanks for your help. Paul

    added by admin: Paul, I am going to built a mini solar charger with some power step up circuit in it to power one (3.0~3.5v) of white led lights I have with intention to test it in a similar style. I will place here my testing results. Seem, for the 120 mA light, the batteries do not receive enough energy and remain undercharged.

    Comment from/about : charging | Permalink

  69. I am using a MAHA MH-C401FS charger for my eneloop AA 2000mAh batteries.

    In the formula (12/100 x mAh = hrs), why do you devide by 100???

    Thanks and regards,

    Added by admin: Hello Henri, I very much value your note! Typo! It should be 12/1000 x mAh = hours of battery charging time. 1000 mAh = 1 Ah to convert ampere hour to milliampere per hour. In addition I included 4 calculation examples up on the page for 2 different size batteries and chargers with 2 various output currents. Can you see them?

    Comment from/about : AA battery charging time calculation | Permalink

  70. Hi,
    Thanks for the quick response but it still does not match my charger specs. What is the 12 in 12/1000?
    My battery is AA 2000mAh 1.2V
    My charger details are:
    Slow charge current: 300mA
    Input voltage: 12V DC 1000mA

    Thanks again

    added: I learned about this from an older book “Electromotance and Electrochemistry”, batteries power source and charging, but nothing too extra special. What are your charger specifications that don’t match, is it a power adapter or some unique charger for use in a car environment et cetera? What’s its “Output voltage” for the 300mA charge current? Do you intend to charge 1x AA 2000mAh 1.2V batteries or 10x of these connected in series to 12V? NiCd or NiMH?

    Edit: I have done some research; “battery conditioning and battery rejuvenation” please look at this forum at first reply. Supposedly this camera bag charger performs with problems, it prefers and prefers-not certain battery types. I was wondering whether it’s related, let me know, thanks:
    forum post

    Comment from/about : AA battery charging time calculation | Permalink

  71. Plz help me. How much current, voltage and time is required to recharge the 1320mAh, 3.7 volt, Li-ion battery. Plz mail me on my email id.

    Comment from/about : Pramod Mulik | Permalink

  72. U give examples of 1.2 volt battery. But my battery is 3.7 volt. So can be any effect on charging time.

    added by admin: Hi Pramod, I will try to help why not. There is also charging for 9 volt battery among others AA, AAA, D, C or specific. Can you take a close up macro photograph of the text which shows on this Li-ion 1320mAh, 3.7 volt battery in question and send the image to me (send the original large image file as it originally comes out from the camera so I see the details on the body of the battery more clearly.)

    I could include this 1320mAh, 3.7 volt, Li-ion battery cell type in the charging time calculator. Do many people use these batteries, where are they applied most often and in what devices? Are you guys from a battery university or something?

    Comment from/about : Pramod Mulik | Permalink

  73. I’m not interested as much in the 12/1000 battery charging formula but I wonder how you calculate the numeric variables for each of your conversion unit pairs? Big variety and all of them with perfectly accurate precision. Would you be interested to work for us? (long term job, travel and accommodating inclusive) My email is being submitted via this form. Sorry I cannot find contact page. Waiting for your reply

    Comment from/about : Michael McTrent | Permalink

  74. How long do I need to charge my NI-CD AA 3000mah 10 VOLT battery can someone help me?

    Comment from/about : Noob | Permalink

  75. I also found a better and/or cheaper digital camera battery charger and accessories on this page, not only a charging method.

    Comment from/about : Digital Camera Battery Charger | Permalink

  76. I have a 7.2 v 1700mah batery pack. I want to use the menu accucell6 turnigy NiMH. What changes need to be changed to be able to fill my car batery rc? and how long it takes?

    @Vicky – can you please elaborate more on the battery pack and what you need to make of it exactly? Could you paste a link to this batteries pack in question, if it’s on a hobby models web site? Cannot say accurately what’s the plan.

    Comment from/about : vicky | Permalink

  77. LED flashlight / battery / charger supplier

    Introducing electronics E-Young Co., Ltd – of leading electronic products ( flashlights LED, batteries and battery chargers, and related accessories ). We are exporter from China, various batteries widely used for all led flashlights, various power tools and many electronic products. Please take a look at our website.

    Comment from/about : LED flashlight – battery – charger supplier | Permalink

  78. Hi. I have a Jessops BC300 battery charger and I can’t see on it what the output capacity is on it so I don’t know how long to charge a 9V NiMH HR22 175 mAh battery. All the charger says is Model PC14UK PRI : 220-240V 50/60Hz 9W

    Battery spec says : 9V-2X (9V 14-18mA 0.162VA and specs for AA and AAA batteries.

    added by admin: I looked at it and found the same charger with very similar box, with the identical specs, but by Energizer.

    Manufacturer: ENERGIZER
    Model: PC14UK
    Input Voltage: 220 volts to 240V ~ 50 to 60Hz 9W
    Output Voltage: AA -2x ( 2.8V === 155mA to 170mA 0.476 VA )
    AAA – 2x ( 2.8V === 55mA to 56mA 0.18 VA )
    9V – 2x ( 9V === 14mA to 18mA 0.162 VA )
    Dimensions: 110mm x 70mm x 35mm
    Weight: 250 grams

    If the 9 volt 175 mAh battery was charged with a 15mA charger ( output current within the 14-18mA range ) it would require 16 hours charge time. With the maximum 18 milliamperes output power the charger produces for 9 V NiMH, it would take 13.4 hours time. I don’t know if this charger has some automatic switch-off time limits (say 5-8 hours each circle and then auto turns off, you’d need to repeat it 3-2 times, hoping it’s not discharging at first at the beginning of each start.) Best are the manual turn-off chargers. Let me know how you went! In the battery type specs, the 22HR is probably a suggested charging time, if it was purchased in a pack ‘specific charger + battery’ in one, which could well be the case. Most probably with charger having 10-12mA charging current for 22 hours length ( quick calculation 240.6hr per 1mA with 175mAh battery ). Isn’t the battery NiCd ?

    Comment from/about : Mark | Permalink

  79. Maybe i missed it somewhere, what state of (dis)charge is used to reference the table.

    Comment from/about : Initial charge for calculation table | Permalink

  80. My converter refuse to turn fan, what will i do so that it will do so? Please can converter charge itself from its output voltage?

    Comment from/about : Stephen | Permalink

  81. Will my charger over heat if I replace my nica 1.2 volt 600mah batteries with a higher rated mah battery? The batteries are going into a Shortridge Flowhood.

    Added: The battery charger should not overheat as it will power the battery or batteries charging process with the same output. What is the exact battery and the charger specifics you plan to combine. However, measure the state of the battery after it was charged if it’s sufficient. And also watch the charger how it behaves in a different times/limits scenario. How did you apply the battery charging time calculator with your items?

    Comment from/about : kelly chapman | Permalink

  82. With using the battery charging formula 12/1000 x mAh = hrs I managed to easily calculate for process of charging a 120 ah nickel cadmium alkaline battery bank and to get the most appropriate charging time length. I worked the charging time out, for this type of battery, by adjusting from mAh to the full Ah rate by simply multiplying by 1000 times what this calculator gave me. This was to get back to character 1 for ah/ampere-hour from mAh/milli-ampere-hour. In other words; 120,000 Milliampere hours ( 120000 mAh ) = 120 amp hours ( 120 ah – ampere hour ). Now it seems the charger charges my battery very well according to some correct principle I came out -with the help from the above (the calculator on this page I mean).

    Comment from/about : 120 ah nickel cadmium alkaline battery charging. | Permalink

  83. […] Originally Posted by VPD24193 I currently have a set of chateau rechargeable batterys in. Is there a way to check the battery life on the scanner and how long should I charge the scanner for? You can check the battery voltage by pressing down on the volume knob. The number on the top by the RSSI is the battery voltage. As far as charging, it is better to charge the batteries outside the scanner. The charge time depends on the battery type, the mAh ratting. And the charger mA. I am not sure what the uniden chargeing circuit is rated. If I would to gues I would say about 150 to 200 mA. To figure out the charge time try this: Rechargeable battery charging time and mA current calculator | Convert to units and units of various measures … […]

    Pingback from/about : 346xt – The Radio References | Permalink

  84. Wonderful battery charging calculator.
    One question still not answered. So here it is again.

    Are there are any voltage restrictions to recharge the batteries.

    Simply to say, “Is it ok to charge a 4.8 V NiMH Battery with 9V if the current is limited to 100mA.”

    Or is it the current only that matters irrespective of the Voltage.


    Comment from/about : Voltage restriction | Permalink

  85. […] The math. Keep in mind you are not charging a battery from zero typically. Here is one perfect battery charge time calculator … for batteries charging. The unit starts to complain when 3.5 volts is registered. Note that the unit does not have smart […]

    Pingback from/about : BCD396XT Battery Charge Rate Consume Rate – The Forums | Permalink

  86. Have learned how long time aa batteries should be charged and with what current. At first I thought that I can use an older NiCd battery charger to recharge NiMH batteries, with it?‎ Yikes. It would be incorrect … as it might charge NiMH batteries by taking a very long time or such combination could not charging well at all.

    Comment from/about : Time to recharge aa battery. | Permalink

  87. i have 2 volt 1500 ah what is will be the charger capacity?
    or 48 volt 24 pcs each unit is 1500 ah what will be the charger capacity? how many ampere the charger should have?

    Comment from/about : what charger capacity to be used | Permalink

  88. The calculator is wrong. The charging is only 66% efficient (150 mah results in 100mah charge in battery).

    To get correct numbers you need to divide the hours by (0.66).

    Comment from/about : Darwin | Permalink

  89. I have 2 pcs. 1.75v NiCad batteries 700 mah each. How many hours can I charge it to my 5-12.5V 450-700 MA battery charger?

    Comment from/about : genfree | Permalink

  90. Your NiCd charge time calculation is great. 600mAH Nicd battery charged at 300mA takes only 1.5 hours?! It should take at least 600/300=2 hours, put in ~50% for charge inefficiency, at least, the charge time should be about 3 hours I think.

    added by Admin:
    Interesting opinion thank you. There are differences with nicd and nimh to consider. I have noticed you use expressions; “it should take at least, ~50% (is it a suggestion for some ~ extra time? The ~ for efficiency of battery charging or battery performance after the charge is made?), should be about 3 hours”. Could you pls make it exact with calculations and how they exactly should work?

    Comment from/about : NiCd charging time | Permalink

  91. nimh charging time -> This is a very handy web tool to calculate nimh charging time for my nimh batteries charging time sellection and mainly it was quick to choose my nimh charging times.

    Comment from/about : nimh charging time | Permalink

  92. I have six (6) – 1800 mAh batteries in my battery pack? Should the charging time be adjusted to compensate for having more than four (4) batteries? I am charging 6- 1800 Ni-Mh at 600 aH.

    Comment from/about : More than 4 batteries in pack | Permalink

  93. I need to order an ENI TIME AA 1.2v 2300ma Rechargeable Ni-Mh Battery 4-Pack Part FLA0654 in an online store. Please advise if you know of any reliable place with small or bulk shipping.

    Comment from/about : THOMAS P DEMOPOULOS | Permalink

  94. Just bought an electric vehicle (Leaf) and wondered about the possibility of developing charging times for these lithium-ion batteries, as well as other Li-ion batteries like drills, saws and other cordless equipment. I know the output voltages are different for these types of batteries than for AAA, etc. The Auto batteries charge capacity is rated in KWh rather than mAmps so a conversion is needed there, and chargers can be 120, 240 or 440 V (in the US alone). Amps in are determined by voltage. My car has readouts for estimated charging times, but these may not be accurate. This might be timely with the advent of more mass produced electric vehicles.

    Thanks for the wonderful site.

    p.s. I enjoy doing these types of things, too. I drive my wife crazy because I’ve gone over to using metric weights/volumes as much as I can in cooking (live in the US). If I could contribute to your site by figuring out from databases or other sources for more food items than are on the site, I’d be happy to do it.


    Comment from/about : Lithium-ion battery | Permalink

  95. And how can i difine charging time of a battery?
    I want to know ( 12v – 7.5 mAH ) What dose it mean ” mAH ” ?

    Comment from/about : KHURAM SHEHZAD | Permalink

  96. I’m inquiring about the charge times of alkaline batteries, either single-use or rechargeable (which are basically the same thing, the label is misleading), since they require low current, could there be a calculator added for chargers of 5 mA to 100 mAh? Or can it basically be the same assumptions as charging an NiCD cell? Since Alkaline is charged at 1.5v, NiCD and NiMH use 1.2v voltage. Wouldn’t it charge properly or require longer time due to the capacity not being known or difficult to tell due to the serial number or model?

    Comment from/about : Rechargeable/Alkaline Batteries | Permalink

  97. I just want know, when charging why don’t you care about the voltage.

    Ah, actually there it is in the step number 1 of the charge time calculator – I have just noticed – 1.2 volt and 9 volt battery voltages as per different rechargeable battery types.
    Thank U

    Comment from/about : Theja | Permalink

  98. Hi there,

    Can you charge D batteries with a rating of 3000mAh in a charger with a rated capacity of 2500mAh?

    The D batteries are Rayovac Platinum and the charger is an Energizer CHFCV2.

    My impression is that it will charge them, it just may take longer. Please let me know if this assumption is correct as I do not want to have a fire or create and explosion.

    Thanks in advance for your input.


    Comment from/about : Tony T | Permalink

  99. Hi
    According to your calculator it would only take 1 hour to recharge a 9v 200 mah battery in my Uniross X-Press 300 charger. The chargers manual says it takes 11 hours to charge a 160mah battery, so a 200mah will be even longer.

    Am I missing something?

    Best regards
    Bob J

    Comment from/about : 9v 200mah recharge | Permalink

  100. Hi Bob,
    Thanks for the note. What are the charger specifications at the back, is it 300mA output charger? And what is the specific output of this charger for 9 volt batteries?

    Your 9 Volt batteries seem stronger. As you can see this calculator deals with much weaker (correct) process with 9v batteries that are charged with 30 mA to 100 mA — it’s what I had in disposition when making the calculator and I looked at several chargers too (some of which though state a complete non-sense.)

    Have you tried to calculate for the correct time manually? Can I look at the manual? : hobbymaker at gmail com

    * Make of a new/separate battery charging-process calculator, which will be only for various 9 Volts rechargeable battery type/sizes, will be practical. ( 9 volts have slightly different calculating formula.

    Comment from/about : Rado | Permalink

  101. I have Lithium Ion 3.7V nominal voltage, 9.6Ah Nominal Capacity, recommended 1.6 A battery. How long should I keep it on charge and how much does it cost to charge per hour? It is for my battery bicycle.

    Comment from/about : Sharon | Permalink

  102. Sharon,
    Thank you for your comment. A battery bicycle?! Great, I would like to be more specific and reply in detail including the cost per charge or per hour; but could you please input more information I need?

    What are the charger parameters and also any info on what the manufacturer suggests.

    What are the lithium battery technical data – should I assume the numbers relate to the battery only. I can be more specific if I had:
    – no “Vdc” number is mentioned, as in nominal charging voltage and at some +, – of few degrees temperature?
    – put separately the Nominal Voltage of your Lithium Ion Battery and specs of the Charger For This Battery?

    Could you provide photographs of both the battery and the charger you are supposed to use, to charge it with?

    Comment from/about : Rado | Permalink

  103. can i charge my rc car 9.6V 3000 mAh battery with a 9V 850 mAh adapter? if yes how long should it take? my rc car has a 2 x 9.6V 3000 mAh NiCd battery and can i replace 1 of the battery pack with a 9.6 V NiMH 4200 mAh which means 1 x 9.6 V 3000 mAh + 1x 9.6V 4200 mAh NiMH battery to operate?

    Comment from/about : jeff | Permalink

  104. I am confused if this chart is referring to the individual cells within a battery pack or the total of the battery pack. I have a 4 cell AA 400mah 4.8v battery pack for a small radio controlled boat. The charger supplied is 250 mah. That is all the information provided on the outside of the battery pack/charger. How long should it charge at that rate to be fully charged? I do not wish to over charge as I understand you risk a problem of exploding batteries etc.


    Comment from/about : Indy | Permalink

  105. Indy, yes correct overcharging batteries or incorrect charging technique might damage them more than just lower/shorten their life span and you do not want that to happen surely. this is easy; when batteries are connected in series, the capacity remains constant while voltages add. Whilst with the parallel connection of batteries, voltage is constant but capacities add. Is that 4.8 volts battery pack put together from four 1.2 volt NiCd batteries type ( nickel–cadmium battery or NiCad battery) or the NiMH batteries type ( nickel–metal hydride battery or Ni-MH ), can you specify this? The intention is to charge them in the set pack in series 4.8v right? ( all 4 batteries connected plus to minus ) Or in parallel? ( e.g. disconnected from series connection, charging each battery separately, but all four together at the same time at 1.2v each )

    Comment from/about : Rado | Permalink

  106. Dear friends

    I want your help in order to complete my solar light project.

    I have a li-on battery of 3.7 at 2300mah that is needed for the led lights.

    My question is the following.

    What kind of solar cell i need to have (cell’s voltage and wattage) in order to recharge the battery correctly during the day light?

    I have to inform you that the amperage that the led lights have as a load is approximately around 150mah.

    Thanks in advance and best regards.

    Comment from/about : Stefanos Konstantopoulos | Permalink

  107. Is it OK to charge a 12v drill battery with a 18v 0.7A charger? It’s A NI-CD 1200mah cordless drill BATTERY. If so, how long will the charging process take please?

    Comment from/about : cliff | Permalink

  108. Can I upgrade my 9.6 volt 1000 mAh battery to a 9.6v 1600 mAh ni-cad in a RC car ?

    Comment from/about : Chester | Permalink

  109. I do not see any reason as to why couldn’t the battery be exchanged for the one with a higher capacity in milli ampere hours. It is only matter of mAh increase by 600mAh units whilst at this time it maintains equally same battery voltage. It is not a voltage change therefore there should not be an obstacle for the battery upgrade.

    Comment from/about : Rado | Permalink

  110. Can I replace my 1100mAh Canon battery with a 1700mAh? It has the same volts just higher mAh – want to make sure it will work in my camera before ordering.

    Comment from/about : Ann – battery replacement | Permalink

  111. Ann, certainly the battery can be replaced from the 1100 mAh for the one with higher 1700 mAh power storage capacity. It will hold the power charge for longer when in use.

    Comment from/about : Rado | Permalink

  112. Does this Charge Calculator base its output charge times on the batteries in question being at a zero state of
    charge or are the Charge Times listed for a given battery the same regardless of how much charge remains in
    the battery at the time they are put in the Battery Charger?

    I ask this because I’m using a 250 mA charger and at the time I put my batteries in my charger, most of them
    still have one-half or more of their total 1.2V charge still in them.

    Within a half hour I can put my volt meter on them and they’ll read 1.35-1.37 V. I’m afraid if I leave them in
    any longer they’ll over-charge to the point of ruin. (which I may have already done based on several dead
    batteries that no longer hold a charge.

    Other than this confusion on my part, I really found this calculator helpful. Thanks for your help.

    Comment from/about : What State of Discharge | Permalink

  113. A while back I damaged 4 near new batteries by not switching between NiCd and NiMH on the charger. And that hurts as they were the better quality kind.

    The voltage 1.35-1.37 V does not really say the battery capacity potential is already reached. From this volts reading, the charging process can take another ~70% of the whole charging time.

    Are you able to fully discharge your batteries and then fully charge them all together? This is the preferred method. Also, what type of batteries are they? A charger can first drain batteries completely at the beginning and only then start charging to 100%.

    Here to your question; not just occasionally I use a different travel charger, while each of the batteries is not equally discharged, I simply charge them at that state as they are. Later on at home, my main charger discharges them and then charging goes on, which fixes their memory to normal (if they are smart.) A few of my batteries I’ve been using for 5+ years without any problem. This way, those bad ones MIGHT be fixed, so worthy to try.

    Another thing I do, batteries which aren’t charged anymore enough for a torch and radio for instance, I do not charge them yet. First I place them into a TV or video remote control. When they stop working there, then I use charger. It’s just a very quick and practical routine!

    Comment from/about : Rado | Permalink

  114. Please help me. I have a battery charger on which the information given is power INPUT: AC 220v 50Hz, OUTPUT: DC 1.4V and I have rechargeable battery of 2100mah, 1.2v which I bought new, so can you tell me how much of time in hours will it take for the first time recharge for 2 of these batteries at a time?
    Thank you very much in advance.

    Comment from/about : somi | Permalink

  115. Hello Somi,
    Could you supply 3 additional kinds of information for charging those batteries in twos, as the needed info is missing.

    1. is it a charger which charges the 1.2 volts batteries in pairs – 2 batteries at the time

    2. what is the charger’s output in milliampere [mA] – e.g. 400 mA or 210 mA etc., if it has different milliampere numbers mention them all), also is it NiCd or NiMH type and is it a rapid charger?

    3. what battery type are they, NiMH or NiCd and the size AA or AAA?

    Comment from/about : Rado | Permalink

  116. I have a RC helicopter but the battery it uses takes forever to charge and then allowance is approximately 10 minutes time of flight consequently having have to recharge the battery again and again. The battery specs are 3.7v lithium polymer battery plus draws 150mAh power. My question is if I buy a 3.7v with a larger amount of mAh for instance 2000mAh with the same voltage plus type and size, will I generate an increase in the actual usage time without damage to the el. motor on this remote controlled electric helicopter?

    Comment from/about : Lithium Polymer | Permalink

  117. How long time does it take to discharge a rechargeable battery in question.
    Specifications of the battery:

    600 mAh power output – usage 0.5 Watt

    Comment from/about : krishna | Permalink

  118. I have developed a charging ckt that I can set the charging current to any value from 160ma to 1 amp. At 1 amp my circuit shuts down in 5 minutes and disconnect the batteries from the charger. All the batteries test good on a load tester. I can with these set up conditions, charge several 1.2V batteries in series. Question: Is one amp to much for recharging?

    Comment from/about : Vince | Permalink

  119. I have (3.6V, 8.74mA DC) harvester, and I want to calculate the time to charge a battery (AAA 800mAh, 1.2V)
    After charging I found every 10sec it charges 1mV, how many days do I need to charge the battery fully by using that harvester?

    Thank you and warm regards

    Comment from/about : Battery charging Energy and time | Permalink

  120. What kind of energy harvester do you have, is it a circuit or something simpler or more advanced? Anything renewable? That is interesting concept.

    If it produces 3.6 volts constant, do you intend to connect these 3x 1.2 volts 800 mAh AAA batteries in series? Let me know, I could calculate the numbers for this.

    Comment from/about : Rado | Permalink

  121. Vince,
    Do you mean 1 amp for 1.2V D, AAA or AA rechargeable batteries? What sort of circuit do you have (“ckt”) with what sort of output?

    Comment from/about : Rado | Permalink

  122. I’m looking if you can help me in charging me batteries with automatic charger schematic circuit that could charge 3xAA 1200 mAh batteries with monitoring leds during the charging time, but when the charging time is over it should cut off but always stay on line reading status of the batteries, for example when the batteries in the charger need to be recharged it should be done fully automatically.
    Awaiting your prompt action. g752
    Thanks in advance.

    Comment from/about : NiCd automatic charger | Permalink

  123. This is GREAT stuff! I was hoping a website like this for charging times would exist. I found the information on the battery and on the charger and it told me it’s 13h. THANK YOU!

    Comment from/about : Jaxx | Permalink

  124. The information this page provides is extremely helpful to me as I have quite a large variety of different rechargeable type batteries to charge. Also I find building my own specific chargers to be a lots of fun. I have been using LM317 etc. and proper resisters to get always the correct charging current. I use this C/10 formula for the program. I never rush any charging time. Thank you very much for putting this web page together.

    Comment from/about : David Connolly | Permalink

  125. I am in desperate need of a NI-MH Battery Pack
    Model BT 1028 3.6V-550mAh
    Do you have them or know where I can purchase these batteries? It has to be the exact power BT1028 3.6V – 550mAh pack model and for multiple recharging of course.

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