Battery life

I have three Pentax batteries for the K1 which get rotated in the camera, and always re-charge as soon as they get depleted. Recently I get the impression they don’t keep a charge anywhere near as long as they used to, is this something others experience? Any recommendations for reviving them? Given their cost I don’t want to replace the batteries unless there is no alternative.

Lithium batteries are only good for a limited number of recharge cycles - I have seen 1000 mooted elsewhere. The deterioration is slow and steady over their lifetime, but in the end they will need replacing.

I have seen figures for electric car batteries, where the same thing applies.

Thanks John, I have just read that lithium-ion batteries have a limited life of 3-5 years even if they are not being used; that means it is possible to buy a “new” battery that has been on a retailer’s shelf for some time so will give a reduced period of use. That is something to think about when looking for a source, a bargain may not be as good as it seems. And having just discharged one battery to zero and plugged it into the charger I have just learned that is the worst thing to do!

Li-Ion batteries are at their best at between 30 and 80% charge - for your phone as well as your camera.
They are sensitive the the ambient temperature as well.
That said I have the same set of batteries for my K5ii as when I bought it. Admittedly I haven't used it much very the last couple of years, but they still hold their charge well, unless it is really cold.

Not long after I bought my K-3, I bought a USB charger for about 12 quid which came with 2 third party batteries. In use, I don't see any difference between them and the Pentax original.

Just sayin'...

Haven't seen the original v third party battery discussion for a while!

I use Pentax, Energiser and Maxsimafoto randomly rotated as they deplete and I haven't found a scrap of difference between them .

Yep, agree with davidwozhere

No discussion from me. I convinced myself ages ago that OEM's aren't worth the price premium.

And for your electric car too. EVs are best left at around 50% charge if not being used, don't know if that also applies to camera lithiums.

Worst thing you can do to a li-ion battery is to run them flat.( from the manufacturer)
They should be charged as soon as you see there power has dropped for best longevity.
I have 3 li-ion brought in 2012 I rotate them ( when I remember) and not had problems with losing power, but from experience with these type of battery I know there life in now short “ after 8years that’s not bad” so will be ordering another three soon”

For myself I always use several batteries, when i don't use my pentax for a while I always remove battery from the camera (I do the same for my car )