I know I should, but my calc's batteries just don't need replacing that often (maybe every 4-6 months), rechargable batteries and a charger are sort of expensive, and I'm not sure how to discharge them fully to avoid that "memory effect" (I use rechargable NiMh AA's in my camera, and I try to recharge them only when it won't turn on, but the lifetime still seems to be getting shorter).

Memory effect doesn't seem to really be a concern anymore. The batteries seem to work okay even if you charge them before being completely ran down. But I've read that it is a good idea to completely discharge them then give them a full recharge every few months or so.

One problem that can happen is when you use a cheap charger that uses a timer instead of actually detecting when the batteries are done charging. If you charge the batteries without being completely ran down, timer-based chargers can overcharge the batteries and ruin them quickly. They also seem to not charge the batteries anywhere near full capacity, so you don't get your money's worth of runtime.

NiMH and Li-ION rechargables have no memory, where the old NiCd do. Most rechargables are NiMH nowadays.

actually, that is a myth. when they are getting recharged/discharged a small amount for thousands of cycles, a effect may develop but this is very hard to replicate, even in a lab. It is more of a problem with equipment in space, as these charge and discharge with solar panels for thousands and thousands of cycles infinantely.

it doesn't really matter, even on Ni-Cads

reference: section 2, paragraph 2, line 1

http:// www.repairfaq.org/ELE/F_NiCd_Memory.html

I'm one of the old-fashioned people that still use non-rechargables and still codes on paper.

TI should create a custom rechargable Li-ion power cell tailored specifically to the TI line.

Just like Nintendo did for their GBA SP... But we would have to buy a new calculator.

no just replace the batteries and battery door whith a Li-ion pack

I saw on the Science Channel this solar powered recharger. They even have a portable one that you can stick on your car's window. Does anyone use that kind of charger?

This is what I have my spare ATX power supply for.

Hmm, I never thought of using an old computer power supply for a calculator before. That's a good idea! I should make something that plugs into the calculator in place of batteries.

I use computer power supplies fr everything, they are cheeper than voltage reducers. I use one of them for charging my calculator

How depressing...non-rechargable battery users outnumber recharchables users 2-1 (of course, with such a small sample size, it's hard to draw any meaningful generalizations)...

I get my batteries for free, so I just use what comes. I'd use rechargables in the other case, but disposables are better on life anyway (in my experience).

I use NiMH. I don't have a problem with having to replace them too often, and when they get low, I dig out the spares, and you need spares weather or not the batteries are rechargeable. So why not? Besides, with two sets of rechargeables, if you keep both charged and know where you keep them, you never have to go battery hunting.