P3009 battery Frankenstein project

Yeah, I would replace 12 and 24. You can't really know the condition of the other modules without charge testing, but that's time consuming. Right now my attitude is that if I get a bad module I'm just going to replace it and get on with my life. You can literally spend a month charge testing (and that's if you have two chargers)

Yes you have to pry the buss bars off gently. I cleaned the buss bars and plastic covers by soaking them overnight in mineral spirits, and then blowing the goo off with compressed air. It worked very well. I also sand blasted the buss bars to get down to clean copper for a good contact.

I cleaned the modules by soaking them in vinegar to neutralize the KOH. Until you do this, be very careful about getting that stuff on you. Wear gloves, and safety goggles. Once it's been neutralized you can brush off the crud with a toothbrush, then rinse them in clean water and dry them completely.

Also check the voltage sense wires carefully to make sure none are broken. They can have very small breaks that you can't see, so use an ohmmeter to check for continuity. You might want to clean them with vinegar also, and again, be sure to rinse them and dry them carefully.

Vincent: I don't have the DTC list handy, does he have anything there that wouldn't be solved with a cleaned up battery?

 

When I did this project last year I cleaned off as much sealant as I could, and my impression was that it hadn't done anything to prevent leakage. But my battery has been running for over a year, and I haven't had any codes. Worst case scenario to me is that I might have to take it apart and clean it the next time it pops a P3009.

 

Bumping this thread because I had a module fail in the rebuilt battery. I thought people might be interested to know how long the rebuilt battery lasted. According to this thread I originally rebuilt the battery in October of 2010, and the car had about 170K on it. It is now March of 2014 and the car has 220K on it.

In the weeks leading up to the p3006 code, I watched the scangauge as the voltages got rougher. I frequently saw the Vhi and Vlo voltages greater than 1.5 volts apart, but it's hard to tell with the scan gauge whether those readings actually occurred at the same time. Sometimes it was clear that the low voltage reading had been taken while the battery was under load, while the high voltage reading was taken while the battery was being charged.

I also made note of which block of modules were reading low (blo) and found that although block 5 was the most chronically suspect, but it was usually blo while the battery was charging, while block 16 was blo while the battery was on load. As the hi and lo voltages got more erratic, block 16 spent more time as the lowest block, and block 5 only showed as lowest when the charging cycle got more pronounced. Finally, I saw the voltages greater than 1.2 volts apart while the engine was off (car was ready), and the dreaded red triangle still hadn't appeared. About 5 minutes later as I was driving the warning came up. The battery went into a charge cycle, brought the state of charge (soc) up to 89%, and the voltages stabilized at about .4 volts apart. I reset the code and continued driving. For a week. It flashed the code a couple of times during that week, but after a charge cycle, the voltages stabilized again and I could reset the code and keep driving. (Today is Sunday) This past Friday I was driving home, and the code flashed, so I reset it, and continued home. It flashed again. I reset it and continued. It never flashed again, but I could see the charge cycle go nuts. Sometimes it showed the soc at 34%, yet Vhi was 19.2 and Vlo was 18.8. Another time it showed 84% soc while the voltages were 13.8 and 13.2. Eventually I saw a 99% soc. with voltages in the 18V range, and still greater than 1.2V between bhi and blo. I figured it was time to take the battery out and fix it, even though it was still running, and hadn't coded for about 20 miles.

I guess I was lucky that it was so cold. The battery temperature started the trip at about 24 deg, and ended at 58 deg.

So I got the battery out and measured the voltages. Highest voltages (this is modules, now, not blocks) is 8.17 on modules 1 and 38. Two modules are at 8.10, and module 32 is 7.19. So that's my bad module. I could replace the 8.10 volt modules, but at this point my replacement modules are just as suspect as the rest of the pack. I've been holding them on a charger for the last 3 years, using the parallel arrangement that's discussed earlier in this thread. Every once in a while I take the pack apart and let the voltages decay, so I can see if any modules have failed. Several have, so they have been discarded. I also periodically run each module through a charge/discharge cycle and record the data, just so that when the battery in the car fails I will have a better idea of which module to use for a replacement.

As luck would have it, I did this last month. So I've chosen my replacement module and I'm putting it back together now.

 

The thread you're reading describes the process. There was another thread called "battery autopsy" that described some of the earlier steps. But the "frankenstein" in this case refers to taking two dead batteries, testing the modules, balancing the modules state of charge, and then putting the whole thing back together.

 

Yes, the car is still up and running, but the Frankenstein battery isn't. The car had about 170k miles on it when I rebuilt the battery, and it lasted a few years, until the car had, something like 210k miles on it. At that point, I still had modules I had been keeping on the charger, so I picked one and replaced the bad module, and put it back together again. It lasted several months before another module went bad, and I did it again. The next time a module went bad was only a month or so later, and I decided it wasn't worth it to keep taking the battery out of the car to change one module, so I bought a "remanufactured" battery for about $900 (not from ReInvolt, but I don't remember the company off the top of my head). That battery is still in the car, and the car is still running fine with 260k miles on it.

I still have the MRC chargers.