Analyzing, refurbishing/repairing a dead hybrid battery pack (2000 Honda Insight)

[MetroMPG]

Hi eq1 - no, I didn't check the blinking light subcode - in fact, that's the first I've heard of it!

Moving the sticks around would have no effect electrically - they're a series string.

It's possible there might be differences in heating / cooling based on stick location in the pack which might affect cell health:



In my pack there appears to be a trend from best to worst discharge capacity based on row (on average, best at the top, worst at the bottom). But I wouldn't conclude this is a design fault without confirming with data from other peoples' packs.

So I didn't bother moving any sticks around. (I actually only pulled 3 or 4 sticks from the pack while analyzing them; the rest I left in the case).

[user removed]

Originally Posted by eq1

You mentioned you had a P1449 code; did you ever check what subcodes you had, the 'blinking lights' codes?

Also, when you put the sticks back in the module, would it make sense to put the highest capacity stick where the lowest one was, the second highest where the second lowest one was, and so on?

I thought the same thing. An analogy would be rotating tires to even out the wear. Rotating sticks to even out the capacity and rate of deterioration.

Maybe next time, for now congratulations on resurrecting the pack. If you have issues in the future, then at that point in time you may look to see if there is a pattern that repeats itself, which would be potentially correctible with a pack rotation strategy.

regards
Mech

[rmay635703]

Originally Posted by Old Mechanic

I thought the same thing. An analogy would be rotating tires to even out the wear. Rotating sticks to even out the capacity and rate of deterioration.

Maybe next time, for now congratulations on resurrecting the pack. If you have issues in the future, then at that point in time you may look to see if there is a pattern that repeats itself, which would be potentially correctible with a pack rotation strategy.

regards
Mech

On FLA cars the battery nearest the pwm controller tends to die fastest, this may be a valid strategy (to a point)

I think most insight packs can be restored somewhat but you may end up with a tinker's pack that needs a little charge each day,

I think I could live with that, too bad the insight options around here are so blasted expensive.

[eco_generator]

Nice results. So I take it that you do not plan on replacing any sticks, then?

[MetroMPG]

If all I need to do is periodic balance charging, then I can live with a 75% capacity pack.

So, barring any unexpected surprises (when the car goes back into regular service in a few months), I won't be replacing any sticks.

[eq1]

Originally Posted by Old Mechanic

I thought the same thing. An analogy would be rotating tires to even out the wear. Rotating sticks to even out the capacity and rate of deterioration....

Right, I read what you wrote and was more or less suggesting a variation on that theme. I should've said something like, 'Would doing such and such, similar to that Old mechanic dude's idea....'

[Formula413]

If I remember right the subcodes for P1449 are battery deterioration, battery deviation, and battery overheat. The first time my car threw P1449 was after a long down hill stretch with constant regen, so I think that might have been an overheat code, but I didn't know about the subcodes so I didn't check. The second time I was able to check and it was battery deterioration, and the code was set right after the car quickly exhausted what it believed to be a nearly full pack, so that would make sense. If I were to allow assist to function normally again it would do the same thing in short order.

As I understand it, the P1447 code is for battery degradation and is more likely to point to one or more damaged cells in the pack, which makes me optimistic that mine could be saved by rebalancing.

[MetroMPG]

Rebalancing, possibly.

I had another thought though:

Don't forget that the other thing my pack analysis did was cycle the sticks fully and recover "lost" capacity (at the expense of some cycle life). The dis/charge currents during cycling were quite a bit higher than the grid trickle charger/balancer: 10 & 7 A respectively, vs. 350 mA.

This is why Robert Smalls encourages occasional "hard" exercising of the pack in his excellent thread: http://ecomodder.com/forum/showthrea...vic-13610.html

[eq1]

Originally Posted by MetroMPG

Hi eq1 - no, I didn't check the blinking light subcode - in fact, that's the first I've heard of it!...

As I read elsewhere, P1449 has 4 subcodes that offer more specific info. You can take a paper clip and jump two pins on the OBDII connector, turn ignition on, and the dash board trouble lights will blink out sub codes - long blinks for the tens digit, short, quick blinks for the ones digit. Longer pause between each unique code that's stored... I think these are OBDI conventions or system features. Hard to describe which pins. I'll see if I can find a link to where I got this info, which has a pict. It's Mike Dabrowski's website, I believe...

The P1449 subcodes are 72, 73, 74, and 78.
72 - battery module overheating
73 - battery cell overheating
74 - battery module individual voltage input deviation
78 - battery module deterioration

Here's a url:
99mpg.com/mikestips/readingtheblinkcod

[eq1]

Any updates on how well your rejuvenated pack has been performing? I'm just about ready to jump in to my own pack, doing the same... Any more tips, tricks, advice about setting up the super brain? Looks like you switched to autocycling at some point in your process: any reason to discharge/charge manually versus auto? I was thinking about adding my own experiences with the process to this thread, once I have them: any objections to that?