I just revived two very old packs.
One pack, I had destroyed a cell in (the end cell, if you recall a thread I did MONTHS ago.... I was running a nimh pack, and one of the cells on the end had swelled up).. Me, being a huge scaredycat, I never charged that pack, and finally sent it in, maybe, a week ago.
These packs are Elite's 5000mAh Packs, 6 cells.
The other pack, is in good shape, well, was in good shape, and I haven't charged these packs ever since that incident..
I received a pack, just fixed from Mike @ CheapBatteryPacks.com (Bought em from there)... Never buying NiMH packs again, I paid a little over $100 for two packs.. Dumb noob back then, and still a bit today!
Anywho, I decided to plop em on the charger last night, seeing if I could get these working again. When I left em in my little battery case (a cheap alu case from harborfreight), they were full charged.
When I tossed em on the charger, the pack that was fine was about 7.65Volts, and the one that I got back was 4.65 volts..
Yes, 4.65 volts.
Damaged pack:
After the initial charge, took a little while, but understandable considering it was at 4.65 volts.. Charging at 2.5Amps, it took quite awhile, took in about 500mAh.. I was in a good mood, thinking, cool, it's still in good shape! Until I discharged it, it only took about 600mAh out.
Now I was scared.
I set it on overnight, (yes, overnight), in a ceramic pot. With a sandbag over it. I put my BC6 on cycle, 5 times. I put the charge at 1.5A, and discharge at 0.5A.....
When I woke up this morning, it was on discharge 4 (only needed one more charge after this), and it was already running at 460-something minutes!
Speed ahead about an hour, it finished, finally quit beeping at me, and I found out on cycle 2, it started coming back to life.
It now went from 500mAh, to a little over 4000mAh.
Needless to say, I was a very happy camper this morning.
I decided it was time to work out my nondamaged pack, and it took in 200mAh..
Why it took in less, I don't know, it also lost about 250mAh... Which was very weird.
It's now on cycle 4, and it's discharged up to 4650mAh!
And I haven't even run it yet!
So I'm a very happy rawfuls right now... You can doubt me all you want..
I shit you not!
Now I'm only scared, on running it, yes, I run brushed, but once in awhile I'll run it on 30%, brushless, for my friends to use.
No, this is not a legit writeup or anything, because it's very messy.
Just wanted to share a story.
If you have very old packs, try cycling them a couple times, with very low discharge and charge rates.
It usually works!