Cell 1 = 260mAh from 1.65v [ rested voltage ] new , uncharged
Cell 2 = 280mAh from 1.67v [ rested voltage ] new , uncharged
Well , disappointing to say the least , resting voltage after being discharged is about 1.45v
I threw the two batteries in my cheap charger [ 4 bay that tries to push AA's to the limit = I like this charger ] and after quite a few hours of being recharged [ I wanted to give the cells every opportunity ] they came of my charger at 1.85v
After resting the batteries overnight , they were at 1.81v , and am currently discharging them in my Powerex charger @ 500mAh
If you look at the label , 2500mWh [ so V x A = W ]
If we divide 1.6v by 2500mW , should be 1500mAh [ I think ] , and I dont see it ...
No , its a cheap ass $10 4 bay charger thats like 10 years old , its called a "MEZZO" , and it will drive a AA battery to what ever voltage it will tolerate .
My AA's will charge from about 1.36v to 1.46v depending on the individual cell , most go 1.43 to 1.45v , and then sag to about 1.41v or 1.39v , most nimh will hold 1.36v or better for long term ...
Some of my little AAA actually hit 1.49v if left in long enough , yeah this charger bares watching !
But from what I understand Nizm is supposedly 1.6v , so if they are 1.65-1.67v they should be fully charged ...
And the resting voltage when empty is so high , something like a powerex would be useless .... [ on these cells ]
Im currently charging the cells again so will see how high I can drive the voltage , as the charger stops charging when enough internal resistance is met ...
[ Which is why some of my AA's charge to 1.36 or 1.37v = higher internal resistance ]
You need the powergenix white charger to get the most out of these batteries. Also, one single deep discharge can destroy these batteries. I think they are considered dead when they hit 1.4V under load.
This time I left the batteries in the charger much longer , till they got a little warm actually ... Still 1.91v hot of the charger
left them overnight to stabilize .. Then discharged @ 500mAh ...
Cell 1 / 1244mAh
Cell 2 / 1347mAh
So no reward there , well , lets try round 4 .... Also left for a longer period to stabilize , I will charge and discharge one more time to see how they go , then charge them again , and let them sit for a week or so and discharge to see if they self discharge ...
Those Powergenix are pretty fragile. I have a bunch of them. So far I have lost one and I have two more which are rapidly getting worse. They do not take well to a deep discharge at all! Like your discharge results are showing they are hard pressed to make 1300mah. Mine have been cycled quite alot and the older they are getting the more self discharge is increasing, although it isn't too bad yet but in my cells that are getting bad the self discharge is getting more and more noticeable after a few weeks of sitting. All this being said I do still like them in most of my torches. The brightness increase is very nice but not all torches will benefit from the extra voltage.