5hr into the discharge now......122.4v

still updating sheet every 15mins

 

This should take longer, perhaps much longer due to the fact that we've "reconditioned" all the cells, and they should have higher capacity. Data every 15 minutes isn't necessary at that level. 30-60 is fine.

Take tap voltages now and record the voltage at the top of the chart.

 

taps voltage updated

 

Can you see the issue? The two questionable subpacks are near zero, but 5 of them are very strong.

How much time do you have to continue the discharge?

Can you work to use automotive bulbs to drain the strong ones to 12V?

 

the pack is still discharging @114.5

do you want me to get the bulbs now and discharge the stronger ones?

 

On second thought, grid charge to 158V + 30minute, idle charge one time and then grid charge until you have to go to work.

I can't see any way those two subpacks don't have shorted cells, which renders them useless. B3/B14 is also in question. The fact that there are two notably higher suggests all but those two are weak and unlikely to perform well.

So, 2 bad, 1 probably bad, 6 questionable, 2 good.

 

hey steve just a qick update not sure if u ca make anything of it.

from the last grid charge which was on sunday into monday morning about 8 and a half hours, the battery work very very good 8/7 bars on the soc, assit/charge full bars and autostop work great plus no recal for about 2 days (the second day which is today) i had to use the ac today and it drop to 4bars on the soc, took the ac of and drive for a short distance and it charge back up to 6 bars on the soc.......do you think that it might still have a chance on bringing back the subpacks?

p.s the car never work so great since i had it......

 

Repeated deep discharges will reclaim lost capacity up to a point. When working directly with sticks, 3-5 cycles is the limit. Beyond that, you don't get much - if anything at all.

In a few cases, cycling of this nature can reduce IR and improve self-discharge somewhat due to reactivation of dormant material, but it's not common.

IIRC, you've done two deep discharges. You could do up to 3 more to see if you get any improvements. If you do, you should record some sort of data to confirm that you're getting benefit like how many miles between recals or something similar you can measure after every iteration.

The downside is that you have such a disparity of strength in the subpacks. When deep discharging, you get to a point where the strong sticks are just driving the weak cells in reverse for far longer than is necessary. Since you've already been in the pack, you might consider the following:

Purchase 11 resistors. You would then short the resistors across the battery terminals. They'll get hot, but they will drain each stick individually without unnecessarily driving the others in reverse.

Alternatively, if you can find some 12V 3W or 4W automotive bulbs, they will do the same thing but a little more aggressively. Discharge each subpack to 6V.

Reassemble and grid charge for 4 hours, car charge 3X, then grid charge for 8 hours.

 

Ok cool well that's a weekend task.....

Thanks for the info

Will update as I go along....

 

Oh by the way how many bulbs do I need to get?