[S Keith]

You likely have some bad bacon there. It's 12 year old IMA pack. Pretty much a certainty that it's a dog, but the price was right for the risk. I've kept my mouth shut to prevent a jinx...

You need to read the IMA codes. For your DC-Dc to only work in the 1400-3500 (or so) range, this pack is probably in pretty bad shape. There could be something else wrong with that pack. Getting the codes read will help diagnosis.

As always, make 100% sure your 12V is healthy (Get it load tested) and your grounds are good. Probably not an issue in this case, but it's always good to confirm it when chasing IMA issues.

Your first grid charge should have been for 24 hours or peak (175V) for 8 hours. If you did this or close to it, a second grid charge very unlikely to fix it.

If you're not discharging your packs, I recommend you do so to this and your original pack. Your original pack is likely suffering from massive voltage depression due to overcharging and may have suffered capacity damage simply from the excessive number of trips to 100% SoC via grid charging.

I recommend the following for both packs:

1. Grid charge to peak voltage for 8 hours, not to exceed 24 hr.
2. Discharge to 135V with 2X 250W bulbs in series.
3. Discharge to 60V with 2X 60W bulbs in series.
4. Grid charge for 2 hours.
5. Attempt to Car charge at idle. If the IMA light remains lit and it refuses to charge, abandon effort and revert to grid charging. If the car will charge the battery, attempt to charge for a total of 20 minutes or so. It may take multiple IMA resets to force charging for that long. You know you're done when the charge cycle terminates very quickly and the SoC gauge goes to full.
6. Grid charge for 8 hours if you were able to charge the battery with the car or for 24 hours if not.
7. Discharge to 120V with 2X 250W bulbs in series.
8. Discharge to <12V with 2X 60W bulbs in series.
9. Repeat charge cycles above (5 & 6).

I recommend dual bulbs because I have popped a lot of single bulbs, and it's really annoying.

The car charging is optional; however, there is evidence to suggest that higher current charging from a deep discharge can help reactivate the cell materials further improving capacity and lowering internal resistance.

I normally recommend a single deep discharge to <2V but given the age and history of your original pack with its existing failure to respond, I am reluctant to do so.

Given my personal experience with Insight and HCH1 sticks, it's unlikely that 20 of the 40 sticks you own will perform well enough to make a functional pack. Stick level work is very time consuming, and doing it right requires high load equipment and test method consistency.

The good news is that the pack deep discharge process essentially does exactly the same thing as most stick refurbishment techniques, so you know that your sticks will be as healthy as possible after these deep discharges, so no refurbishment will be necessary, and you will merely need to devise a means of sorting.

If these deep discharges of the pack don't work, I recommend the following stick sorting method:

Make yourself a nice table to record all the data.

Buy something like this

• Grid charge the pack to peak voltage for 24 hours.
• Disassemble and let the sticks rest for 24 hours after grid charge.
• Measure and record resting voltages. Sort by voltage descending.

--------

• Starting with the highest voltage stick, attach the tester
• Attach a separate voltmeter
• Activate the tester until one of the following is reached:

1) 30 seconds is achieved, record voltmeter voltage and a time of :30.
2) 5.4V is achieved on the voltmeter, record time and 5.4V

Repeat the above load test for all sticks.
NOTE: This will be hard on the tester. You may want to wait a few minutes between tests and apply forced air for cooling between tests.

Repeat all of the above for the other pack.

Select the sticks that went for :30 without hitting 5.4V and then select the sticks that went the longest before hitting 5.4V. The best 20 are the ones you want to install in your pack. Sort them from best to worst (highest to lowest V at :30 and longest to shortest time to 5.4V). When assembling the pack, pair the strongest with the weakest within a given pair as that will minimize the voltage drop for each tap and report the most balanced voltage to the BCM. The voltage taps are on the orange plate to which the big orange cable is attached. Pairs are the adjacent sticks between those wires.

This gives you a means of quickly and cheaply testing all your sticks to determine those capable of delivering high current. The chance of success is low, but this method has you with only another $25 invested and about 4 total hours of bench time.

Good luck,

Steve

EDIT: REMEMBER, READ THE CODES FIRST, AND CHECK THE 12V/GROUNDS BEFORE ANY OF THE ABOVE!