docnjoj wrote:I actually did something like that charging them at about1amp till around 3.7 volts and then going to 5 amps which is still way below 1C. I really screwed those cells though and they did last a while but never were as good as originally powered.
I keep looking for the 16AH or possibly 10AH and get 4 of them but I am in no rush. The Luna 36 volt pack I bought works fine.
I guess I've never discharged any pack with a heavy current load. I've only managed to leave the motor controllers turned on for a day or so, or in the case of the MT's 32Ah pack, a week or so.
This is because I rarely use the MT trike much because a windshield is a luxury item I've come to love.
Something about being warm and comfy. ...and I left the power switch "on" on the MT trikes' front motor for over a week before I caught the discrepancy.
Anyway I've never had the occasion to put to the test what happens when a Lithium battery is over-discharged with a load approaching or exceeding 1C.
I saw about a week ago 16Ah 6S multistars were in stock and priced at 71.something dollars but that was then
I do believe I get more than twice the range from one 32Ah multistar pack vs two 20Ah packs made from 5Ah packs. I kinda know why but hesitate to type that much or verify the data.
I had a 3s pack of EIG NMC cells drained to zero when someone played wiht my lighting switches on CrazyBIke2 a few years ago, and was able to revive them and they operated normally for me since then, although I never really use them above maybe 0.5c (about a tenth of their capabilities), as the lighting pack.
Left all the lights on (including car headlight) on the trike one night, I also killed one cell in a 4s pack of those, actually reversing it (guess it had less charge than the other three), and THAT puffed it up.
The other three are still ok...
I use 4S packs for lighting now but I use 5 5Ah packs in parallel for a solid 6 hours of continuous operation if all the lights are lit and the cameras/monitors powered up. (everything's on separate switches)
Since most of my night or 'dangerous conditions' riding involves just to the store and back I tended to recharge the lighting pack(s) about twice a year (built two lighting packs thinking I'd ride more often in 'those' conditions since I could but I don't)
I've yet to reverse a battery's polarity ((either on purpose or accidentally) but as I mentioned earlier I can "never say never" because anythings probable.
I have seen battery chemistry damaged that way (reversed polarity) but I've yet to have one do it under my observation.
I might note that the very first packs I accidentallied below 2V with a less-than-1C load were recovered using the previously discussed methods then the cells continued their Life As Motor Power Cells for another 4.5 years.
I devised this method a while ago by observing how the cells reacted to stimulation (sounds sexual) and while I'm not a battery engineer, I designed many a device that had to be battery-powered for portable operation, so I basically had to learn the ins/outs of primary and secondary battery chemistries available at that time.
I apply this general knowledge of 'what to expect' with lithium chemistry and have yet to be disappointed while also noting lithium's many differences. Different yet similar. Similar yet different.
...did I mention NiCd sux?
So far so gud...