Is it OK to mix NiMH batteries?

On Wed, 20 Aug 2008 10:08:39 -0700, wrote:

I had a set of 4 PowerEx 1800 mAH batteries from several years ago. I
threw one of them away because my charger wouldn't charge it anymore, so
now there are 3 of them left. I just bought a new charger, which came
with 2 Duracell 2000 mAH batteries. Is it OK if I take one of the
Duracell batteries and combine it with the 3 PowerEx batteries to form a
set which I can use in my camera that takes 4 batteries?

I wouldn't. I would buy 2 more duracell 2000 mah batteries and see if I
could find some 1800 mah batteries to mix with the powerex.

On 20 Aug 2008 18:29:46 GMT, ray wrote:

I had a set of 4 PowerEx 1800 mAH batteries from several years ago. I
threw one of them away because my charger wouldn't charge it anymore, so
now there are 3 of them left. I just bought a new charger, which came
with 2 Duracell 2000 mAH batteries. Is it OK if I take one of the
Duracell batteries and combine it with the 3 PowerEx batteries to form a
set which I can use in my camera that takes 4 batteries?

I wouldn't. I would buy 2 more duracell 2000 mah batteries

Good.


and see if I could find some 1800 mah batteries to mix with the powerex.

Not so good. The remaining PowerEx batteries have not had
1,800mAh capacities since they were new, several years ago. In
fact, they're unlikely to all have the same remaining capacities.
One could still be good for 1,000mAh and another only 600mAh. You
can get a rough idea of how their capacities compare without
requiring special equipment if any devices that use a single AA cell
can be found (such as a 1 AA cell flashlight, used to discharge
them) and a charger that's able to charge one cell at a time (many
cheap ones can only charge them in pairs). The remaining capacities
will be roughly proportional to how many hours/minutes it takes to
recharge a fully discharged AA cell. The longer it takes, the
greater the capacity. Then by comparing these times with how long
it takes to recharge either of the new, fully discharged 2,000 mAh
Duracells, the state of the old PowerEx batteries can be estimated.