How can I tell which rechargeable AA is bad?

I have 8 AAs, 4 bought in 2005 and 4 in 2010. They don't really work under that well with my camera. Freshly charged is ok but after 3 days they don't work. With my Lacrosse charger which indicates for each individual battery cell, they still report, 1600 or 2,100mah (2005 and 2010). I have also used the voltmeter and they give similar decent reading, 1.38 or 1.42V.


I went out and bought some Eneloops with a charger - BQ-CC55 - which this site has a great review on. This charges the cells individually and has light indicators for each. All my 8 AAs had the red blinking light. Is this a good enough test to show that all my 8 batteries are bad? My other new Eneloops and my recent Energizers work fine on it.


Thanks.

What does the Charger Show?
What it pumped IN the cells, or what got OUT?

Charge them, leave 2 days, put them into with only a discharge program
Check numbers after completion
(Throw away the 1-2 cells that might be bad)

As NiMh battery`s get older the internal resistance gets higher, the higher the resistance the faster the battery will self discharge without use, also when you charged they will get hotter.

A lot of smart chargers will check the battery`s internal resistance before it starts to charge, But if the internal resistance is too high the battery will be rejected.

John.

What camera? Years ago I got a Nikon point and shoot and it would not work with any NiMH even the Nikon branded ones. Basically if the voltage dropped below that of a fresh cell even a tiny bit it'd throw a dead battery warning and shut off. Pissed me off, I expected better from Nikon and couldn't even get a reply from their CS.

N8N said:

What camera? Years ago I got a Nikon point and shoot and it would not work with any NiMH even the Nikon branded ones. Basically if the voltage dropped below that of a fresh cell even a tiny bit it'd throw a dead battery warning and shut off. Pissed me off, I expected better from Nikon and couldn't even get a reply from their CS.

Click to expand...

Nikon F100 film camera, takes 4 AAs. Film SLR.

yellow said:

What does the Charger Show?
What it pumped IN the cells, or what got OUT?

Charge them, leave 2 days, put them into with only a discharge program
Check numbers after completion
(Throw away the 1-2 cells that might be bad)

Click to expand...

I have a trip soon. I need to alloc some time. However, I do recalled after the 3 days of being charged, they didn't work on my Nikon camera. I put them in my LaCrosse BC-900 charger and did a discharge only. Each of the 4 cells reported at least 1,600mah before I stopped it. The current being used was 500mA charge which was 250mA discharge.

Do I need something like a ZTN battery tester so it test the battery under load?
It seems like the batteries are fine under low drain devices.

It is off a film SLR, Nikon F100.

NiMH increasing impedance and dying out? Does this include the LSD cell like eneloop as well? Or this only affect the earlier normal NiMH with no joules left after few month? Kinda worrying since I have few eneloop still in the package, fresh and unused, like 6 years ago...