A variety of batteries are available on the market. This leaves many people confused over which battery to use. Its more than just a matter of whether they’re disposable or rechargeable, it’s what can give the best usage. Alkaline and NiMH each have their own advantages and disadvantages.
“AA” alkaline batteries produce 1.5 volts electrical charge at a rate of 2,400 milli-amp-hours. Think of it as pouring a 1.5-oz. cup of coffee 2,400 times in one hour. Most alkalines are not rechargeable but have a slow discharge rate. NiMH batteries are rechargeable, but the discharge rate is 25 percent a month. Volts are 1.2 with a rate up to 2,900 mAh. The difference in power is subtle. Alkaline is good for low power devices, NiMH is good for high power devices.