How can I test NiCd or NiMH batteries to see if they’re still good?
Due to their flat discharge profile and recharge ability, it is difficult to define a simple quality check for NiCd or NiMH batteries. For fully charged batteries, a battery tester which measures closed circuit voltage can be used as a general guide to determine if the battery is “good” or “defective”. A voltmeter which measures open circuit voltage is not a reliable method for evaluating rechargeable batteries and is not recommended for this purpose. The most accurate way to measure the performance of rechargeable batteries is to monitor time and operating voltage during controlled discharge.
