CH wrote:
>>
The CR-V3 I have seen on eb*y only quoted 1300mAH, even the voltage may be
slightly higher I don't see how it can be better than the 2100mAH or higher
NiMH in capacity.
<<
The NiMh only has a 1.3-0.8V for each cell during discharge.
Assuming 1.1V average for NiMh, for the 4 nimh cells in series gives a total of
2.1Ah*1.1V*4 = 9.2Wh. (a bit more for newer Nimh cells)
Assuming you are correct and the cpacity is 1.3Ah for rechargeable CRV-3's:
then for two CRV-3's total energy is 1.3Ah*4V*2 = 10.8Wh.
So in this comparison there is only a 17% advantage to the CRV-3's (as you say
not much) But at end of discharge the Nimh's are at a lower voltage so it
depends quite a bit on the design of the Olympus electronics: what is the
cut-off voltage of the electronics. This can make a huge difference to actual
capacity in usage. The endpoint for the CRV's is 3.6V and for the Nimh's 3.2V.
It seems in actual use, in many cameras the CR-3V's are much better so cut-off
volatge may be high. Early Sony camcorders had a similar problem, as the
batteries aged the apparent battery life dropped in half because cut-off
voltage was set too high.
Steve's digi camera comparison tests estimated a typical ~ 70% greater
capacity using the CRV3 replacewment over NiMh:
http://www.steves-digicams.com/2003_reviews/rcrv3.html
Camera User comments on this web site agree, if you believe they are
independent(!):
http://www.smallbattery.company.org.uk/sbc_crv3r.htm
>>'I bought two sets of chargers and batteries a few weeks ago for my Olympus
>>E-10 and they are fantastic; The first test from the initial charge I managed
>>320 mixed shots i.e. at least 40 of them were flash, some were waving the
>>camera around to get the autofocus going and all were with a 5 second
>>preview. Prior to this I was lucky to get 50-70 shots with NiMh and was
>>frankly peeved with the batteries dying at the worst possible moment'
<<
>>'I took my E-20 and set the timer to take a picture every minute (flash off,
>>5 sec auto review). My resolution was set at HQ at 1/8 compression. The
>>camera ran for about 10 hours and took 368 photos before it powered down.
>>Anyway, it looks like these guys have plenty of juice. Very pleased.'
<<
The site claims much better results in digi cameras, but also points out the
FL50 flash should not be used with the CRV-3 batteries, as cells are overloaded
and the internal current limit operates by the high current. This is actually
generally true for really high currents the NiCd's are usually better even than
NiMh and for even higher current the SLA's are the best.
The first user comment above sound like Iddi's experience with Nimh.
Regards,
Tim Hughes
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