Let me continue chatting with myself... On the "ooh! shiny!" justification, I bought this charger, so here's some info:
It is "smart", probably dV/dt, and runs at 450mA, about C/5 for the AAs and C/2 for the AAAs. The internal contacts are hooked up the same for AA and AAA so unless it does fancy sensing, it doesn't know which kind you loaded.
There is a top-off charge for a few hours (more than 1, less than 4). It's a pulse charge at a low duty-cycle. Was seeing 1.46 between, 1.58 or so during. After top off ended I saw 1.38 and no pulses in the 30 sec or so that I looked.
There are 4 slots, and four battery status indicators, indicating charging, some ways through charging, and "done". There are only 4 LEDs, though, with a light pipe making each channel's pair of LEDs light up the dots in 2 of the charger's 4 battery symbols. Indicators for cells 1&2, and 3&4 are optically the same.
1st cycle the 900mAh AAAs charged in about 2 hours, one a little warmer than the other, but neither "hot". Second charge of those at work here and the IR gun said 98 and 108 F respectively. Not sure why, but it was the cell that was cooler during the 1st charge cycle that was the warmer on the 2nd.
For two cycles, cells given time to fully top-off, I ran a discharge on the UBA4 to 650mV using a stepped rate routine starting with 1C. The number in parentheses is the sum of the rest of the steps, which go down to C/20:
The 900mAh AAs, 2 cycles, discharged to: 1C (.05C)
-----------------------------
AAA #1 / AAA #2
831 (996) / 598 (780) (The warmer cell was the 831)
730 (841) / 576 (765)
The 2500mAh AAs, 2 cycles, discharged to: 1C (.05C)
-----------------------------
2064 (2338) / 1947 (2338)
2081 (2310) / 2080 (2347)
That's all I know for now. Pretty much enough, for the charger anyway. I'm curious about these energizers given how crappy the 2500s I got 2 years ago were. One of the AAAs appears defective. If it was just dormant the 2nd cycle should have given more capacity.
Pack was $20 at Wally World, so for, figure, a $10 charger, it seems pretty decent. If I don't use it, I'd feel comfortable giving it to a friend who doesn't care about the details...with, of course, Eneloop cells. And, yeah, the eneloop chargers, being individual channels, are much better. That 4 cell one for $20 with 4 AAs was/is a bargain.
