Pentax K-m battery

Is it possible to use rechargeable Lithium batteries in this camera?:

I can't remember if CRV-3 batteries will fit in the K-m or not. If they do (they do in my older *istDL2), then the answer is it's possible, but not advised.

The reason is that the native voltage of a Li-Ion cell is 3.7V. Two of these in the form of rechargeable CRV-3s would make a total supply voltage of 7.4V instead of the 6V the camera is designed for.

Some, but not all, rechargeable CRV3s are regulated to 3V and these are fine, but the cheaper ones are often plain Li-Ion cells kicking out 3.7V and these are not fine.

Pentax recommend against it so if you fry your camera by using them it wont be covered, and the labeling is not always clear so you could easily waste a lot of time and money trying to find suitable cells. Personally, I wouldn't risk it. Stick to either rechargeable Ni-MH AAs or single use Lithiums, both of which are fine and will give good battery life in a K-m

I think there might also be some issues with heat generation, but the answer is the same. Lithium batteries are not advised until the A series cameras and later.

I don't see a real advantage either, those AA li-ion sells are max 950mAh so that's just as much power as a nihm 2800mAh but you can use 4 of those and only 2 li-ion so why half your power?

We're not talking AA cells here Stefan, but button cell equivalents.

Surely the K-m takes AA cells.

My apologies, I'd just realised we were talking at cross purposes but you beat me to it!

Forget what I said.....AA cells for the DSLR K-m, but something else entirely for the film KM.....

With regards the OP, I just used to use Eneloops in mine. Close on 1,000 shots per charge.