What is the best rechargeable battery on the market right now with the highest energy density?

One disillusioning thing I learned about rechargeable D batteries is that the cheaper ones are just “C” batteries with filler. On the other hand, maybe that’s all you need. If you have an application that uses a LOT of current, pick your brand and then get the most expensive variety within that brand. Radio Shack, for instance, has several varieties.

I don’t think rechargeables will hold a charge as long as alkalines, though, so they are best for things that you not only use a lot of current in, but use often.

I play a lot of cassette tapes and my player has a low-battery indicator. I also have a battery tester. This way I am always able to fully discharge one battery at a time–test it to see which one has gone dead–and recently threw away the last of a set of four that I bought thirteen years ago and have used regularly ever since. (They happened to be GE.) They really do recharge a thousand times and in fact are far more likely to get lost than they are to wear out. (by Roger Kovaciny)

Thank you for the post but these do not have near the energy density, or life I am looking for, I have found this site, and they have some very nice packs, but I need to know if there is better batteries out there. http://funadvice.com/r/14purk7v29c rclipos.com