HV battery balancing

Thanks Seilerts......I am only able to read some codes using my "memoscan T605" which does not seem to read any manufactures codes.In relation to loose wiring,fan connection etc,I have removed the complete HV Battery/computer pack twice so far and checked it but found nothing obvious.Would it be the case that the other infomation codes with P3000 could indicate the ECU?.

Thanks

 

I'd like to thank everyone for the useful information. I've been replacing Gen. I Battery Packs and Rebuilding with Gen. II Modules for about a year now and I am just starting to venture into the Reconditioning and Balancing. I figured I'd post my progress (or lack of) and get feedback from all of you. Can it be obvious from the get-go that some modules are not worth the time and/or energy in reconditioning? Is it easier and/or better to just rebuild with 2004-2007 modules? The Gen. I pack I recently dismantled is a 2001 and the modules are measuring all over the map, the bus bars and wiring harness are showing heavy corrosion due to electrolyte leakage. Is it best to buy a new wiring harness in severe cases or can the most corroded harnesses be cleaned and salvaged? (The car had been sitting for approx. 8 months to a year, as it was a state auctioned car.)

Basically, I'd like to know if there is anything that can be assumed from the voltage readings before beginning the reconditioning process? (ie. modules reading 0.14, 0.16 are garbage and aren't worth the time in charging/balancing? Also, is the safety issue in charging multiple modules in parallel only with the Gen. II modules or with the Gen. I modules as well? My modules are reading as follows:

1. 6.82
2. 6.65
3. 6.69
4. 6.36
5. 4.21
6. 2.88
7. 1.37
8. 1.38
9. 1.45
10. 1.23
11. 1.46
12. 0.16
13. 0.26
14. 0.20
15. 0.16
16. 0.16
17. 0.16
18. 0.30
19. 0.37
20. 0.14
21. 0.10
22. 0.45
23. 0.28
24. 0.24
25. 0.29
26. 0.15
27. 0.13
28. 0.23
29. 1.29
30. 1.19
31. 3.09
32. 2.21
33. 2.40
34. 0.45
35. 2.62
36. 3.78
37. 5.83
38. 6.67

Thanks again for everyone's help!

 

I do not think you have anything to gain by using any of those modules considering the leakage problem with gen1 modules.

The only time I would put module in parallel is to balance all the modules intended to go into a complete battery.

The safety issue applies to all the variants of the Prius modules.

The condition of the wiring harness is difficult to asses from a distance, obviously a new harness is best but cleaning with a mild acid to neutralize the alkali may be sufficient.

The buss bars may be treated in the same way and rubbed flat with a fine file or on an emery block.

John (Britprius)

 

thanks much john! my $28 smart charger doesn't even recognize the modules reading 0.16. i was just curious as to if those modules are truly bad or have been just sitting too long and need to be recharged; and will they hold a charge and withstand a load? i think i need a better charger that recognizes extremely low reading modules and will charge manually. thanks -aric

 

If you want to check those pancake-flat modules, connect two in series to a wimpy 12 v low-amp (14v typical @ maybe 4-6 amps), for a few hours and see if they come up enough for your smart charger to recognize and charge. I'm talking abut a typical consumer grade charger used for folks' cars and boats, nothing special. If so perhaps you could try to begin some sort of conditioning/ test cycle after charging them with the NiMH charger. I have tried this and it worked, but then after my NiMH charger recognized them, I really didn't get anywhere with those that had been so flat for so long... ended up replacing the battery with new Toyota one.

 

you could even try a 6 volt trickle charger. that will get them into a safe range to connect the smart charger.

 

hey thanks fellas! i will experiment with some different chargers. i just did a Gen. I rebuild of 38 (2004/2005) modules that are all reading 7.8 - 7.5 today and hopefully this pack will fire up tomorrow in the car. i then have another Gen. I battery pack that i will take my time with and try some different chargers and see if i can't balance 38 cells that will hold charge and withstand a load. what do you guys do with your bad modules that don't hold charge and/or can't withstand a load? recycle maybe? trash? experiment?

 

Be sure to take appropriate precautions such as safety glasses, old clothes and test your safety wash station.

As for candidate module:

• melted "O" ring terminal - this is the only external sign of a failed module

I have tested the safety vent to 1 bar using a vacuum pump but it did not open. If you have a high pressure air source, it would be helpful to find out at what pressure it opens up. Near as I can tell, the "O" ring blows out first to protect the over-pressure, safety vent.

The one thing I've never figured out is how to repair or replace the "O" ring. Perhaps you might have more luck.

Also, can you identify the plastic?

The Toyota/Panasonic patent on rehydrating the modules references plastic welding. I got a kit from Harbor Freight but had no luck matching the plastic rods to the case. My current thinking is if we can find the melting point, a plastic 'spot welder' could be used to close rehydration holes.

BTW, did I mention the KOH electrolyte is wicked stuff?

Bob Wilson

 

wow bob! you are definitely going the distance with this stuff. at this point digging into the modules is a bit over my head. if i can get 38 modules to hold charge and withstand a load i'm a happy camper. all of this information is quite interesting, and yes i did find out indeed that KOH electrolyte is wicked stuff. yikes!

 

BTW, the simple answer is to drop the dead modules at a Batteries Plus. They'll send them to the recycler and the nickel, plastics, and rare earths will be reprocessed into other products including batteries. Don't send them to a landfill, they have too much value.

Alternatively, call a local metal scrap dealer and asked if they would buy either the modules or if you removed the metal, the metal by bulk. This is not a hard process although I don't think we're talking a house payment.

Bob Wilson

 

You could save some of the plastic and after a good decontamination use it for welding any holes in rehydrating experiments.

John (Britprius)

 

As I experimented with the plastic welding kit, I soon realized this is something that requires a mold or form. As the plastic housing gets hot, it soon deforms in other directions. I could not localize the heat enough to achieve a quality bond and the KOH solution 'climbs walls.' Did I mention it is wicked stuff?

I tried various stainless steel nut plates and screws but they could not handle the pressure from ordinary charging gas generation.

The one option left open is to drill-out the pressure relief valve and have a clamped, rubber bulb, close the fitting. I have yet to find a pressure relief valve that shows any evidence of having worked. So my thinking is a KOH proof, thick walled, 'bulb' clamped to the nipple on the pressure relieve valve would work. This would also mitigate additional pressure on even partially destroyed "O" rings ... but I would only want to use modules after a pressure test confirmed they could hold some "n bar" level.

Note, these can not go into a joint manifold because the voltage potential is so high between the end modules it would simply and instantly cause a short via any KOH path.

Now a functional 'bulb' could probably be constructed using clear, plastic tubing if the end can be permanently plugged or sealed. One 'wild idea' would be to marry two modules with both pressure relief valves drilled out and the ends of a single, plastic hose clamped to the nipples. Then the normal potential difference would be:

2*7.2V = 14.4V​

2*8.2Vmax = 16.4V (worst case)​

This is something best tested on my eBike.

Bob Wilson

 

hey bob! i just installed a rebuilt hv pack this am in a 2001. my 12 volt battery is good (brand new) when i try and start the car nothing. the screen shows a decent battery level with no warning symbols. i still have the back seat off and only mounted my pack with a few bolts as i am still making sure everything is working properly. that clicking that i usually hear (because my seats are off) from the hv battery just before the car starts does not happen. total silence. i don't have a scan tool. any guesses?

 

check your hv battery relay. maybe its disconnected

 

Without turning it "OFF", try turning to start, back to IGN, and back to start a couple of times. There is an obscure, inverter interlock signal that come from the inverter, back to the orange plug, and then forward to the HV ECU. I've seen one case where this signal fails but everything else is OK.

If the car starts, leave it running. You will see an ugly error indicator on the MFD.

The signal passes through the safety interlock, microswitch that the battery safety plug closes when the latch goes fully seated.

Just a thought,
Bob Wilson

 

i will double check my hv battery relay and also try the start-ign-start idea also. this was a state fleet car and the back window was smashed out along with the drivers window when i bought it and it took in water. the drivers side floor was soaked thoroughly and with the new york cold winter the car has yet to dry out properly. today the floor carpeting seemed to be frozen solid. there is an unusual hump in the floor behind the drivers seat. could this be affecting the harness? -a

 

its possible, maybe that relay or the hv battery wires that go to the car have some corrosion on them and maybe the relay is corroded

 

Use the "kiss" method that was taught to me "Keep it simple son" and its most of the time, true to a "T"

 

scotman can you recommend a good scan tool for Gen I Priuses that isn't ridiculously expensive?

 

Scangauge 2, 159 at autozone. I have one of these and like it. it can read some of the hybrid system. clear codes, it has this xgauge feature. if you can text you can set up xgauge. you are going to have to contact Linear Logic the company that makes scangauge, tell them that you got a scangauge for your year prius, and they will send you a modified cable for it for free. the cable that comes in the box with the scangauge sets false codes and your brake and abs lights will come on, nothing to be afraid of but the way to clear the codes is to turn the key on and off 3-4 times, or use the scangauge if it picks those codes up

there is also autoenginuity but thats going to run you 5oo plus but its really good. they also have this chinese knock off mongoose cable and the toyota techstream software but I dont know if it works or how good it is. At this point I would try the scangauge.