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Forum: Pentax DSLR Discussion
11-19-2008, 03:16 PM
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This is about right.
Although high capacity NiMH sound like they can contain more energy/power - they unfortunately develop high rates of self-discharge.
To get more capacity into a battery the components like separator have to be thinner - therefore the batteries are more fragile and prone to damage - both physically as well as from over charging or over heating - so although they start off well - they deteriorate pretty quickly.
For example Energizer 2500mAh NiMH have a very bad rep over at CPF's Flashlight Electronics - Batteries Included section with frequent reports of them not holding charge - some as low as only a few days.....
this seems to apply to other higher capacity (>=2500mAH) NiMH - even the best known brands -
ref:
More dying Energizer 2500's...
Duracell 2650 batteries dying
It looks as though the K200D has "inherited" the poor battery behavior of the *ist and K100D -
The Pentax K100D is notorious for being very battery fussy - mainly as pointed out - due to too high voltage threshold/cutoff levels -
Ref: Post #49 (link) in thread - K100D - "Low-Battery" Problem gives details of the meter voltage levels.
Primary Lithium AA's are probably the best - like the Energizer e2 lithiums - as they maintain higher operating voltages - but they are relatively expensive and use-once only.
For rechargeable eneloops are the way to go - please see -
Summary Post #57 (link) of this thread eneloop vs. Kodak Pre-Charged Voltage Maintenance
where I used a Pentax K100D to show that eneloops maintained a higher operating voltage under-load than the Kodak Pre-Charged (otherwise great LSD NiMH).
I get shot counts of between 550-650 shots with well over 50% flash using eneloops - this well exceeds the K100D specs for 2500mAh NiMH - in fact approaches the specs for Lithium batteries without flash.
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