Can you summarize the cycles, e.g.:

Charged with ______ for X hours.
Discharged w/A Watt bulb(s) to B Volts
Discharged w/C Watt bulb(s) to D Volts
Charged with ______ fo Y hours
etc.

Basically, all the charge/discharge cycles you did prior to installation.

Deep discharging to 60V at low current will NOT harm sticks that will recover. If they are marginal, it can push them over the edge, but marginal sticks are going to give you reasons to remove them anyway.

 

I charged with the LPC-100-350 for about 22 hours to 175V
Discharged with two 200W bulbs in series for for 3:45 hours to 132V
Charged for about 17 hours to 169V
Discharged for 2:45 hours to 130V
Discharged with two 25W bulbs in series for 8:15 hours to 60V
Charged for about 16 hours to 168V

All were done prior to installation. This is the pack that gave an IMA light at the start of the trip back from Massachusetts and stopped giving codes at the end of the trip. The tap voltage that is most suspect is 5-4.

 

There's your answer. You charged for 5 hours less to a lower peak voltage.

Typically, after discharging, you will see higher peak voltages than prior, AND you tend to see higher peak voltages in cold weather. On your 2nd and 3rd grid charges you didn't get to 100% SoC. You input 1750mAh short of the prior charge, which is about 25% of the pack capacity.

Nice work. You are a pro now.

 

Good morning,

I noticed that the spread on tap voltages tends to increase as a battery's total voltage decreases. Knowing that the tighter the readings, the better, what would you say would be an acceptable spread at nominal voltage (144V in the HCH1)? It's been stated the 0.2V is acceptable for 100% SoC. I'm wondering about the difference between 100% SoC and Nominal Voltage. Thanks

Jen

 

That is correct. The disparity at lower SoC is greater.

144V open circuit voltage (OCV) is a nearly dead battery. I wouldn't put much faith in those numbers. If you're monitoring tap voltages under a pack discharge, you may see very large variations. Cells can drop out and reverse in the 135-140V range.

OCV of healthy modules should be pretty consistent throughout the usable SoC range (20-80%). I wouldn't expect there to be more than about 0.3V at the bottom.

 

Hi Steve, is there a minimum number of hours/ volts that a pack needs to be charged to when taking it out of storage (144v + 60 mins) before installing it into an hch1?

 

60 minutes good. 4 hours better.

4 hours guarantees you're > 20% SoC if the battery is completely flat. If the battery is less than 144V, it's flat.