Do you keep iPods, cell phones, rechargeable batteries (for cordless drills or cameras) plugged in all the time, charging even if they're already fully charged? Overcharging these products can actually wear down the rechargeable battery more quickly, which means you'll need to replace it sooner. Instead, use personal electronics until the battery is almost out of power and then properly charge it. Once charged up, unplug it and use as normal. This will give you hundreds of more charges and more hours of use with your cordless products.