All it takes is a single cell to be bad, and the battery is bad. The battery is only as strong as its weakest cell.

You shouldn't charge without cooling.

 

Yeah, i got the battery in place with the cover on, and the grid charger also powers the cooling fan (i'm assuming thats enough?)

Also, what voltage do you think i should charge it to each time?

 

That's not consistent with your claim of concern that it overheated. If the unit powers the fan, it's not possible to overheat the battery unless you are charging in hot ambient conditions.

You do not charge to a voltage. The purpose of grid charging is to fully charge all cells to true 100%. This is done on the basis of time and current. You need to input 8500Ah into the battery to insure all healthy cells are fully charged. You need to divide 8500mAh by the output current of the charger. That's the number of hours you charge.

 

Not sure if was overheat or what. I left it on the grid charger overnight and in the morning i had an IMA/CEL which cleared after a little driving & batt. disconnect..

Heres the display of the grid charger.. it charges at about .28amps. the booklet that came with it says to stop charging when the voltage its charging at stops rising for an hour's span of time..


display of grid charger

 

From a KNOWN discharged state or for a severely imbalanced battery: 8.5/.28 = 30.4 hr.

The issue with that voltage criterion is that it may not capture the peak. It's very possible for cells to be at substantially different states of charge meaning full cells can cause voltage drop that offsets the not-full cell's voltage gains - particularly over the course of just an hour.

 

thanks keith.
30hrs was what i calculated too, but i was hoping i was wrong... I've been reading that you gotta discharge/recharge cycle it like 10 times for it to have a chance of being effective, and that would literately take more then a month to do..

I'll try to squeeze in at least 2 times in this weekend and see what that does...

 

Inconceivable that it will take 10 cycles. If you're referring to sources that indicate individual sticks might take 10 cycles to restore capacity, that can be correct, but that's very different than whole pack charging/discharging. With sticks you rarely go below 1V/cell. With whole pack discharges, it's almost impossible to have some cells NOT discharge well below 1V.

Pack level charges/discharges rarely need more than 3 if they benefit at all. If benefit is to be had, you'll get 80% of it after the first discharge.

Deep discharges can kill a pack that behaves marginally well. Recommend your first discharge is to 106V with 2nd and subsequent discharges to 66V. All discharges must follow a 30 hour charge.

If 106/66/66 doesn't help, you can push all the way down to 25V or below, but that's a hail mary.

Concerning your IMA error, in some cases, grid charging with ignition on can trigger fault.

 

Yeah, i did forget and started the car with the grid charger still plugged in and charging, that may have triggered the ima+cel.

Shizal, for the discharge i usually hook it up to the two light bulbs and let it go until they go out and then some, then i disconnect the light bulbs for like 30 min to let the voltage rebound, and then hook them up again until volts is as low as possible. You think thats too much of a discharge?

 

Depends on what the voltage is when the lights go out. You should measure it. Under-discharging may not yield benefit. Over-discharging may push marginal cells into full failure.

There is no reason to wait, allow the voltage to rebound, and then re-discharge. Once the discharge target voltage is attained, stop discharging, then charge.

 

after hours on the lightbulbs, checking it right after disconnecting, the voltage of the pack is like 3-4v. after about a minute it rebounds to 16v tho, and usually keeps slowly climbing...