I have used a brand of NiMH batteries for years with a charger from the same manufacturer. After reading up on batteries I found the following statement on battery university All about chargers

The Ah rating of a battery can be marginally different than specified. Charging a larger battery will take a bit longer than a smaller pack and vice versa. Do not charge if the Ah rating deviates too much (more than 25 percent).

After checking the rating of my charger I found it to indicate 1.2V 500mA. The batteries I have been recharging for years rate at 1.2V 900mAh. So is the charger I have used not suited for the batteries which are from the same manufacturer?


Don't mix up mA and mAh! One is (charging-)current, the other one is overall charge.

mAh = mA x hours, so if your charger charges a battery with 500mA for 1 hour, the overall charge transfered is 500mAh.
To charge the battery up to the full 900mAh will take \$ \frac{900mAh}{500mA}= 1.8~ hours\$.

  • \$\begingroup\$ Thanks I understand it. But If the charger has no Ah rating but only states 1.2V 500mA how can I be sure that it fits the battery. So I can ignore the objections by battery university about the Ah rating?? \$\endgroup\$ – CuriousIndeed May 27 '20 at 12:20
  • 2
    \$\begingroup\$ I assume that the cited statement is referring to charging batteries with different capacitance ratings simultaneously. It is not completly clear, but there is no reason to worry, if the voltage is correct, you will be fine. \$\endgroup\$ – jusaca May 27 '20 at 12:25

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