More NiMH 101, please

Julian Tan wrote:
Hi Tommy,

Yes, the 2300mAh should give you longer battery life. mAh measures
power over time (I think -- my memory of physics studies is a bit
hazy) so in theory, a larger rating will give longer life.


You're correct. Plain simple - 2300 mAh means 2300 milliamper hours, which
is...let's say this way - if you drain battery with 2300 mA current, it will
last one hour, while if you have 1800 mAh one, it will last one hour if you
drain it with lower current, that is 1800 mA, while draining it with 2300 mA
will last only about 45 minutes.



I usually leave the batteries in the charger overnight on the first
charge - not exactly sure about the technical reasons, but that's what
they recommend for nimh mobile phone batteries.


In any case it's a good idea to have good quality fast charger, and if you
do, you can leave batteries overnight or even longer (for weeks) in it
without any harm, since charger after they are full switches to trickle
charging. So, if you do that you only pick up batteries and go. Leaving them
in a drawer will cause self-draining of about 1 % per day...so after 3
months they are empty or after 4 weeks they will loose about 30% of the
charge.
It's also a good idea to completely discharge them every now and then to
prevent from memory effect, which DOES exists, even though some say it
doesn't . It does, it's just much lower than one at NiCD cells.



Regards,
Julian
http://www.shuttertalk.com - the friendliest digital photography
forums on the net!


TommyC wrote:
After going on the same sets of NiMH batteries for a few years, I
just went out and got some new panasonic ones, rated at 2300 mAh
(impulse purchase - I got home and saw that there are 2500 mAh ones,
and I'm sure others will tell me of even more powerful ones).

The older batteries still work fine and I'm going to use them in
another camera I have.

But for the new batteries, can I expect more shots off of them than
off of my old ones? One set of old ones was 1500 mAh and the other
was 1800; these are 2300.

And do I need to do anything special with the new batteries to make
them work most effectively? I put them in a charger, where three
hours later, the "charging" lights had gone out for each cell. Will
they work at their peak at this point, or do I need to do something
else (I just have a plain vanilla Kodak battery charger; it doesn't
"condition" the batteries)?