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I recently bought this Camelion 1.2V AA cell pack. It says 1000mAh. Now I am trying to charge them. But before I do so, I want to know the possible outcomes in three scenarios:

If I were to charge using these values then what would happen if:

  1. 1.2V but low amp for example .44amp?
  2. 1.2V but higher than 1amp?
  3. 1.2V and 1amp?

And what would high or low voltage do?

How should I charge them?

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  • \$\begingroup\$ What does the datasheet suggest? \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 May 15 '18 at 21:02
  • \$\begingroup\$ 1000 amp is rather high for an AA cell. Check your question title. \$\endgroup\$ – Transistor May 15 '18 at 22:07
  • \$\begingroup\$ I dont have a data sheet neither do i know where to look for it. And the title is correct. Search for the Camelion 1.2v 1000mAh cell pack. You'll find them on common sites like ebay etc. \$\endgroup\$ – Syed Suleman Shah May 18 '18 at 19:58
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0.44A isn't that low. 1C for your cell is 1000mA, so a good trickle charge rate is 0.1C, or 100mA. It will take about 12 hours to charge.

you could charge faster, perhaps 0.2C, 200mA, provided you don't let the cell overcharge.

The voltage must be higher than 1.2V or the cell will never charge properly. The charger must be current limited to avoid frying the cell.

You can charge at higher currents, provided you shut off the charge, or switch to a trickle charge, once the cell is full. To do that properly requires a knowledge of the characteristics of NiMH cells. It's more complicated than just using a simple voltage/current supply.

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  • \$\begingroup\$ First of all thank you for the answer secondly it would be great if you would share whatever formula or method you used to calculate the time it would take using the values \$\endgroup\$ – Syed Suleman Shah May 18 '18 at 19:56
  • \$\begingroup\$ @SyedSulemanShah The 1C rating for any cell is just the amp-hour rating (or milliamp-hour rating), ignoring the "hours". So a 1000mAh cell has a 1C of 1000mA. In theory, if charging at 0.1C, the cell would be charged in 10 hours. That's simply because 100mA x 10 hours = 1000mAh. But if we allow a slight loss in charging, around 12 to 14 hours is better. \$\endgroup\$ – Simon B May 21 '18 at 1:01
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Optimal energy storage and discharge will take 10h. So 0.1A until detected temp rise of 2’C. More aggressive charging and discharging will reduce energy capacity by 20% @1A and 50% @ 3A. Keep them cool in operation for longest life.

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