Originally posted by dncraker The problem I have encountered is that certain brands of these NiMH batteries are not recognised or do not seem to work with the cameras.
The batteries test fine for voltage (1.4 volt) on a fresh charge and work fine in all other appliances I use. They just seem odd with these cameras.
Short version: use eneloops
or any confirmed re-badged eneloops - like Duracell Pre-Charged or Sony Cycle-Energy (for
BOTH must be only made in Japan and white top surrounding the +ve button)
Long version - Pentax dSLRs using AA batteries are notorious for being battery fussy and voltage sensitive. I see you have tested the voltage to be 1.4V - but that is open-circuit without any load. It is the operating voltage under load that is important.
NiMH rechargeable batteries native nominal voltage is 1.2V - so this is already at a disadvantage when it comes to Pentax dSLRs - and as they are used, the operating voltage under load sags - depending on the current demand - and this can be as high as ~1.5Amps. (for more details please see this thread -
K200D Battery Meter Problem specifically Post #
23 )
Also as NiMH batteries age - they start to develop higher internal resistance - which limits the amount of current they can deliver - so the operating voltage under load sags even more.......
eneloops manage to maintain a higher operating voltage under load than any other NiMH rechargeables - this is trivial for almost any other application -
BUT for the Pentax dSLR this is a
HUGE advantage - please see post #
28 (link) in the same referenced thread above. (also
eneloop vs. Kodak Pre-Charged Voltage Maintenance summary post #
57 , also please see #
61 )
eneloops are the newer LSD (Low Self-Discharge NiMH rechargeable batteries
Wikipedia link ) as the name suggests they hold on to their charge longer than normal NiMH batteries - higher capacity NiMH (>= 2500mAh) are well known to develop high rates of self-discharge some reported losing their charge in mere days - and this includes the big well known brands (eg:
Ref1 Ref2 Ref3)
I use eneloops and DuraLoops (nickname for the Duracell Pre-Charged re-badged eneloops) and have gotten between 650 (with lots of flash usage) to over 1,100 shots (mostly without flash) in my K100D - and this is with the batteries stored for 1-4 months charged before use....... (see
eneloop vs. Kodak Pre-Charged Voltage Maintenance)