A personal finance blog dedicated discussing such topics as budgeting, asset allocation, 401K, IRA, cash flow, insurance, financial planning, portfolio management, and other areas in personal finance.


Thursday, June 23, 2005

Rechargeable Batteries - An Update

Yesterday I posted about whether or not rechargeable batteries are a good investment. I did a cost comparison between Energizer's AA rechargeable batteries and their standard AA battery. The hard part about doing this kind of comparison is that the two batteries don't have the same battery life. The rechargeable battery does not last as long between charges as a standard battery.

I sent an email to Energizer asking them how long a rechargeable lasts in comparison with their standard AA battery and this is the response I got back:

Thank you for visiting Energizer's Web site and also for your inquiry. I would be happy to assist you.

Combining alkaline and manganese yields 1.5 volts. Combining nickel metal hydride yields 1.2 volts. Our regular alkaline cells are 1.5 volts. Our rechargeable nickel metal hydride batteries are 1.2 volts. Since all devices operate within a voltage range, you should still be able to use the rechargeable batteries. The batteries will not last as long per charge.
However, you will be able to recharge them.

Rechargeable batteries do not last as long per charge as regular batteries.
The advantage of rechargeable batteries is that you can recharge them hundreds of time without having to buy more. You save money in the long run, but you have to remember to recharge the batteries.

Rechargeable batteries are very different from standard batteries. They are not only different in size and shape, but by capacity, voltage, chemistry, and technology as well. As you are aware, there are special guidelines to follow in order to properly use and maximize the life of your batteries.

Battery life is determined based on many factors. The three most important factors are drain rate, the cutoff voltage of the device, and the temperature the battery is exposed to. Generally the manufacturer of the device should be able to give you an estimate of how long a particular battery should last in their device.

Hopefully this information will assist you. If you need further assistance, please do not hesitate to contact us.

Energizer Consumer Relations

It wasn't exactly the clear answer I was looking for. I guess the life depends on how you actually use the battery. Anyhow, it doesn't change the fact that after the intial upfont costs, rechargeable batteries are a good investment (especially if you have lots of kids with lots of toys!).

For those interested, Energizer has a pretty good FAQ section on their website.

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