[SteveB]

It's pointless to keep extra NiMH's in your bag, because they will invariably have drained just when you need them!

Not if they're hybrid NiMh's. That's the point, they won't be flat when you need them and you can use them as a spare set in your bag. Hybrios/Eneloops/Kodak pre-charged/etc hybrids are just better all round than any other NiMh especially in a K100D. The only time an ordinary high capacity NiMh will show any advantage is if you charge them up and use them the same day, you'll probably get 200 more shots under those circumstances. After a few days they will be on par and after a few weeks there's no contest.

[UnknownVT]

The only time an ordinary high capacity NiMh will show any advantage is if you charge them up and use them the same day, you'll probably get 200 more shots under those circumstances. After a few days they will be on par and after a few weeks there's no contest.

The cross-over point between 2000-2100mAh LSD batteries (like eneloop, Hybrid, or Kodak Pre-Charged) and higher capacity regular 2500-2700mAh NiMH is about 30 days - ie: on par at about 30 days.

Regular NiMH lose about 15% of their charge in the initial 24hours, then tapers down to about 15% every 30 days thereafter (ref: BatteryUniversity.com) -
so they lose about 30% of their charge in a month (~45% at 2 months, and ~60% at 3 months).

So charge up regular NiMH on the day (or night before) the shoot - if one's going to shoot a lot - then charge up more than one set.

However as backup or to keep in the camera over long periods of non-use - use LSD batteries - but charge the LSD once every 6 months or so.

[LeoTaylor]

I use the "Impact" 2700 mah NiMh featured by B&H and have all the problems mentioned. Fully and recently charged I can go many hours and 250 shots without any indication of a weak battery. But recently, after 10 cloudy days without use, my K100D lasted 3 shots and my K100D wouldn't even light up. Both batteries were fully charged before the rains came.

Checking the battery indicator first isn't good enough, it tends to indicate full until the last bunch of shots. I just make sure I swap in a set from the chargers if the camera has been sitting a few days.

One charger has a deep discharge feature that you are supposed to use every few cycles. The batteries get so hot the wrapper starts to peal off! I figure my batteries get down to near zero often enough in normal use so ceased scheduling deep discharge mode.

While on the subject of power, does anyone else have a DSLR that loses the clock every time the batteries are swapped? My K110D does this ever since it came back from Pentax Repair. It is not enough of a problem for me to send it back for another 3-4 week repair. It only takes a moment to set the date and time which will last as long as there are batteries inside. That camera is often used with external power, so even the time it would not power up I plugged in the AC adaptor and used it for an evening.

Unfortunately I bought a bunch of these low cost Impact batteries from B&H, some day I'll try Eneloops.

[UnknownVT]

I use the "Impact" 2700 mah NiMh featured by B&H and have all the problems mentioned. Fully and recently charged I can go many hours and 250 shots without any indication of a weak battery. But recently, after 10 cloudy days without use, my K100D lasted 3 shots and my K100D wouldn't even light up. Both batteries were fully charged before the rains came.

Checking the battery indicator first isn't good enough, it tends to indicate full until the last bunch of shots. I just make sure I swap in a set from the chargers if the camera has been sitting a few days.

One charger has a deep discharge feature that you are supposed to use every few cycles. The batteries get so hot the wrapper starts to peal off! I figure my batteries get down to near zero often enough in normal use so ceased scheduling deep discharge mode.

According to BatteryUniversity.com NiMH prefer shallower discharges - they last longer - although once in a while they should be discharged more deeply.

Once a battery has over-heated - so greatly where the wrapper bubbles or even peels off - they are probably damaged and can't be recovered. This is most probably due to a faulty charger that did not detect end of charge properly.

However it's worth looking at Post #49 (link) for use of LSD (Uniross Hybrio) and NiMH (Energizer 2500mAh) in a Pentax K100D - it's in the thread - K100D - "Low-Battery" Problem .

Both eneloop and the Uniross/UltraLast Hybrio seem to maintain their voltages better - which seems to be what is needed in the K100D/K110D.

[jgredline]

I have great luck with energizer rechargeables..I have 3 sets of them and I get some 500 Pics of each set...