Last year I decided to go all "Rechargeable" for flashlights and other devices that use AAA thru D cells.
My main use is for an 8 cell flourescent lantern and 4 cell Maglite (all D size).
They both get used quite often in the Winter season.
I purchased the Accumanager20 and CTA 12000mAh D cells and like both.
This was quite an investment, but well worth it as long as I get plenty of use out of them.
Unfortunately, I didn't use the lantern for a couple of months and 8 D cells went to 0V. I put them in the Accumanager20 and as you can imagine they would not charge due to being at 0V (initially, I was worried and bummed that I had ruined the cells and wasted my investment.
Determined to do what I could to get the cells recharged, I put the cells into the Accumanager20 and used a charged AA size and wire in parallel with each D cell, letting the LED blink around 10 times, then removed the parallel AA cell and wire and moved on the the next D cell.
Once I had all the LEDs blinking, I let the D cells charge for about 5 minutes before removing them from the charger.
I unplugged the charger (making sure that it was reset), plugged it back in and placed the D cells in the charger for a normal charge cycle.
The CTA 12000mAh D cells came up to full charge and work as great as ever.
Just wanted to share how I did this, I couldn't find much information on how to revive a NiMH cell when it has been sitting too long and lost all of it's charge (to 0V).
I do like the Accumanager20, it takes a while to charge NiMH cell of this capacity (12000mAh), but it does so topping them off nicely.