On Saturday, January 1, 2022 at 11:47:11 PM UTC-8, Cydrome Leader wrote:
> Ed Lee <
edward....@gmail.com> wrote:
> > On Saturday, January 1, 2022 at 4:11:38 PM UTC-8, Cydrome Leader wrote:
> >> Ed Lee <
edward....@gmail.com> wrote:
> >> > On Saturday, January 1, 2022 at 1:39:35 PM UTC-8, Cydrome Leader wrote:
> >> >> Ed Lee <
edward....@gmail.com> wrote:
> >> >> > I am using these batteries. Discharging from the (BMS managed side) 8 pins connector seems OK, but charging is not working. It might need the I2C control to enable charging?
> >> >> >
> >> >> > With the battery at 10V, hooking up a 11V supply doesn't seem to do any thing, with the voltage coming up to 11V immediately. Someone reported good result with 12V+ adjustable supply.
> >> >> >
> >> >> > Hooking up to the internal battery (BMS unmanaged side) works, with the voltage slowly coming up from 10V to 11V. Surprisingly, the BMS detects that the battery is charging (blinking status LED).
> >> >> >
> >> >> > How could this be possible? As far as the BMS is concerned, it's just hooking up to a battery with slowly increasing voltage.
> >> >> >
> >> >> > I am also ordering another 12V supply to try.
> >> >> >
> >> >> > Battery link:
> >> >> >
https://www.ebay.com/itm/114762741090?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=114762741090&targetid=1264870804984&device=c&mktype=&googleloc=1014221&poi=&campaignid=14859008593&mkgroupid=130497710760&rlsatarget=pla-1264870804984&abcId=9300678&merchantid=6296724&gclid=Cj0KCQiAlMCOBhCZARIsANLid6ZbSSHrKQORZWqutaBIvMDlPRakT6KjL60ic1mfeQyXaMwvZkFVTl4aAhoREALw_wcB
> >> >> So you bought old dead batteries off ebay and are running into issues?
> >> >> Strange.
> >> >
> >> > The battery is fine, but the BMS is strange. I just don't understand how the BMS could detect that i am charging the battery behind it's back. The battery is only going up a few mV per hour.
> >> The ebay posting makes it clear these are end of life, thrown away, then
> >> pulled from a dumpster and being resold type deals. If the batteries are
> >> perfect like you seem to think, why do you care about the V> >> circuity thrown in?
> >
> > I am just trying to understand how the BMS works. For output, the 20A short protection and 30A fuse is good to have. I can charge the raw battery directly if necessary. More convenience if charge through the BMS, with balancing.
> >
> > The battery should have around 70% to 80% of original capabilities.
> Bullshit. You bought garbage somebody threw away, which was likely
> diverted from proper recycling. Buying used batteries is always a fool's
> errand.
The cell pack itself is good. Bypassing the BMS, I have it charged from 9.6V (20%) to 10.7V (50%) in three days. Someone mentions that the BMS config needs to be reset via I2C. Plan B is to use external BMS, or not at all.
Markings on the BMS did not turn out any result. I guess i have to try every known BMS I2C possible.
It's better to reuse the battery first than to recycle.