Battery Testing question

I have a BC-900 charger and 16 different NIMH batteries that I charge with it. 8 of those are Energizer NH-15 1600mah batts, 4 are Tokina 2000mah and the last 4 are LaCrosse 2600mah batts. When I charge them up on my BC-900 they show capacity being within 10% of stated capacity. Now when I take them off the charger and put them in my EC-741 battery tester it shows only 2 lights and says that the batterys only have 40% of life left? Now I have tested this with all my batts and they do the same thing.(Some range from 20% to 80%) Funny is how I can put them in my camera and as soon as I turn it on the battery light comes on and it shuts down. The batterys are about 2 years old and are not charged everyday. The batterys should be showing more than that on the meter or do I have crap cells? If the charger is putting in say 1900mah into the 2000mah battery and the voltage on the charger is showing 1.49 then why is it so low on the tester? I should just go out and purchase some eneloops and be done with it. What do you guys think?

Flatshovel, it sounds like your cells are suffering from voltage depression. They still have reasonable capacity (at a low discharge rate), but their voltage is sagging under a normal current load.

You might try a few "Refresh" cycles on them. That might bring them back. Often though, this is a sign of general cell degradation. Not much you can do then.

Dave

Your conclusion "eneloops" is probably the right one.

But let's look at what else is going on. You say you "charge" them, and they "show capacity". That is not the same thing. In charge mode, the BC-900 displays the (m)Ah it put into the cells. This is not the same as their capacity. To get an idea of their capacity, use the test mode.

Second, it's practically impossible to measure remaining capacity of a nimh battery, so all that the battery testers can tell you, at best, is empty or not empty, which is the same as trying it in a device and seeing if it works or not.

Thirdly, some digital cameras are notorious for having a very high low voltage switch off, that is, they switch of far before the batteries are empty, and only really work well on lithiums or perhaps eneloops that maintain a higher voltage under load generally..

And the 1.49 after completed charge is with the trickle charge still being applied, bumping up the voltage...