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elhigh 11-10-2015 10:04 AM

New-to-me IMA pack
Scored a 115K mile IMA pack from an '03 HCH on eBay last night. You could have knocked me over with a feather when I found out I had won it with just $250. I hope I haven't bought a pig in a poke.

I have reason to believe it has its own problems, but since my IMA light has been on for about a year - the grid charger isn't helping anymore - it may allow me to kill that idiot light for a while.

And then, while I have a spare pack, I can work on more fully refurbing my existing IMA pack to get it to a much more serviceable condition. Because for all its faults, I strongly prefer driving the Civic over the other vehicles I have to choose from.

Daox 11-10-2015 10:52 AM

Nice find. Planning on sharing the process with us?

jamesqf 11-10-2015 12:38 PM

You could always test the individual sticks, and make one pack from the best ones.

elhigh 11-10-2015 01:41 PM


Originally Posted by Daox (Post 499016)
Nice find. Planning on sharing the process with us?

Absolutely. I'm anticipating it arriving sometime next week, and I don't think I have any volunteers scheduled until after Thanksgiving. The swap is a simple process, and switching the grid charger over will be a doddle.


Originally Posted by jamesqf (Post 499023)
You could always test the individual sticks, and make one pack from the best ones.

That's the plan. I've seen the occasional box of sticks - untested - for sale but for some reason the complete IMA felt like a better deal, especially at this price.

elhigh 11-20-2015 09:14 AM

Okay, some updates:

The IMA pack finally arrived from the seller in Ohio. He packed it very thoroughly and everything looked in excellent shape. No pictures of the box or the unpacking, though I made my Dad who is visiting open the box. Dad custom-makes boxes specifically for when he ships things, and while his stuff always arrives in good condition they're notoriously difficult to open. It kept him busy and happy for a few minutes.

Son #2, I and Dad all spent a few minutes last night swapping the packs. Mostly it's just cumbersome, heavy parts in cramped confines.

Hooked up the grid charger and left it on overnight. Pack started at 155v.

Unplugged grid charger this morning showing 175v on the input. That's a bit lower than I hoped.

Started the car. Fired up on the IMA motor, so that's good - it means I remembered to turn the pack's breaker ON.

12v charging warning light was ON. Hmm.

IMA SOC array bottomed, but climbed to full after a couple of minutes.

IMA light was still ON.

CEL light was still ON.

I'm not surprised about the CEL light. I have a cooked O2 sensor somewhere and insufficient kung fu to figure out which one. I'll take it to a shop eventually. Maybe ream out the EGR valve too. I can do that at home though.

I had hoped the IMA light would go out after a few minutes. No such luck.

The 12v warning goes out above 1400 rpm. This gives me some hope, it suggests the IMA pack is simply too out-of-balance to allow the DC-DC converter to do its thing. Another night of grid charging may wrench it back to where it belongs.

I'm reading everything S Keith has to say about it, him and Snikrepretep. I hope I haven't bought a pig in a poke.

S Keith 11-20-2015 01:28 PM

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,



elhigh 11-20-2015 06:41 PM

This all sounds very achievable and I VERY much appreciate the guidance. I now only have to contend with:

1) Dad's in town. He lives 10 hr. away and is gettin' up there in years. He wants to go to the mountains.

2) My wife is saddled with a large event for the homeless shelter we work for, and her 40+ volunteers who signed up all buggered off, leaving her with only 3 for tomorrow and none for Sunday.

Yeah, "buggered off." I could say what I'm really thinking but asterisks just aren't sufficient. I'm not feeling very charitable toward the vols right now.

3) I get pretty depressed when it doesn't work the first time.

It barely got nine hours on the GC total in the first place; I will give it 20+ and see how it does. If that craps out, I'll dig deeper into it. I have a car to fall back on, and Son #2 can drive the truck.

Nevertheless, I will keep trying. Again and very sincerely, thanks for the help.

S Keith 11-20-2015 06:55 PM

Given #3, in retrospect, I should have spoken up sooner to keep your expectations and disappointment in check.

DEFINITELY go longer on the GC!

On the bright side, you got a killer deal. Since you already have your old pack out, build yourself a discharger:
and discharge it. The above is about $4 from Hope Depot. The board is one of those screened fascia pieces for ventilation. Yank the screens out, and you don't have to drill the 2" holes in it. They're $0.98 each.

If you measure voltage and current, you can estimate your pack capacity.

Good luck!


elhigh 11-22-2015 11:33 AM

Okay, the longer GC didn't work. I left it on the charge for 23.5 hours. GC voltage output topped out at 180 for a while, but then dropped back down to 175-178. Output current never started to taper off. Looks like the pack's a bad 'un. I knew it was a gamble.

I have other motors to drive while the Honda is benched, so I'm going to:

Build a discharger and sock down the original pack. For future clarity, Pack 1.

The Honda is mobile with Pack 2 but the 12v light coming on is a little unnerving. I think Sweetie is happier driving a different car rather than rolling the dice. I tell her it's not much of a roll but frankly I can't blame her.

On the upside Dad and I went to Cades Cove in the Smokies and got to see the sorghum sugaring demonstration. The last time we saw that, he was younger than I am now, and I

Yeah, seven.

jamesqf 11-22-2015 01:07 PM

Also consider that there are many uses for the battery sticks that don't work in a pack. For instance, I have an old battery-powered hedge trimmer that would run maybe a minute on its original pack. Soldered in a couple of leads, duct taped a couple of sticks to the handle (to keep it nicely balanced), and it's run all summer on one charge. Not that I use it that much, but there were 3 or 4 half-hour or so sessions...

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