Using rechargeable batteries in the Bluetooth Mighty Mouse

Question

When I got my Mac Mini I put expensive alkaline batteries in; they lasted for about three days. I then tried rechargeables, even though I read somewhere you weren't supposed to do that. But it was either that or the Mouse was for eBay. The rechargeables lasted for 4 months. The only thing was that the battery display in the Bluetooth Control Panel showed three bars lit instead of five. I don't suppose there's anything to be done about that and it doesn't matter anyway, but I'd be interested to know why there's this difference.
Michael

Answer 1

Thanks, Andy. I could have looked that up for myself, couldn't I? Still better late than never. Here are a couple of interesting things I've found at Green Batteries.
*Why do my alkaline batteries run down so quickly when used in a digital camera (or other electronic device)?*
Alkaline batteries were not designed to meet the very high power demands of today's electronic devices. Alkaline batteries have a high rated capacity, but they can only deliver their full capacity if the power is used slowly. (See chart). Electronic devices such as digital cameras place a high power drain on batteries, so it is much better to use rechargeable NiMH or NiCd batteries for these type of devices. Lithium batteries also work well in high drain applications but they are expensive and are not designed to be recharged.
*Can NiMH batteries be substituted for alkaline batteries even though they are only 1.2 volts?*
Yes, for most high drain electronic applications NiMH batteries are ideal substitutes and you needn't worry about the apparent voltage differences. Even though alkaline batteries are rated at a nominal 1.5 volts, they only deliver 1.5 volts when they are fully charged. As they begin to discharge the voltage of alkaline batteries continuously drops. In fact, over the course of their discharge, alkaline batteries actually average about 1.2 volts. That's very close to the 1.2 volts of a NiMH battery. The main difference is that an alkaline battery starts at 1.5 volts and gradually drops to less than 1.0 volts. NiMH batteries stay at about 1.2 volts for most of their discharge cycle.
Michael