OK, I'll accept that as the only reasonable explanation. Why +ve only though, I can see why the +ve leaks on aa cells because the -ve is a can so probably this is also true underneath the plastic outer cover whereas the +ve is basically a hole in the can.
The line of thin black stuff around the terminal is the "O" ring that is supposed to seal the terminal 'squeezing out.' That goop was the sealant that was supposed to fix the "O" ring loss. Obviously there were unintended consequences. I'm convinced the best answer is to rebuild using the new traction battery modules. They are much stronger, lower internal resistance, and overall a better part. Bob Wilson
So Mj how did it go? Or do you still have to replace the hv ecu? I'm very interested because I may have to do this soon as well. Bwilson - can one get/buy individual new cells? If so where and how much?
I don't sell individual modules. You may be able to others who do. IMHO, modules need to be matched and this means a pool and a smart charger. Bob Wilson
Thanks for that info Bob. Very interesting, so bench charging is very tricky, and yes I agree that all cells should be matched, and may also be preferably the same age as well, thus making sense to replace all the cells at once and keep the others for experimenting etc..My 03 prius (49mpg) will be first in a couple three years from now. My 06 prius (52mpg)won't be needing anything for quite some time I hope. Both cars have run perfectly. Not going to get anything until it dies..don't want a good one to be sitting around of course. So each niMh cell is filled with water? And one other question, can a scanguageII read the cell voltages, or only the entire battery voltage and/or SOC?
The electrolyte is a 6 mol, KOH solution. What happens is small amounts of water electrolyzes and escapes as H{2} and O{2}. Over time this dries out the electrolyte. Adding water can restore capacity BUT it is difficult to reseal the case and the real problem is the gas leak around the terminals of the NHW11 modules. The NHW20 fixed that problem. I don't have a Scanguage so I do not know what it can do. Bob Wilson
Thank you very much for that info Bob. Very interesting and I as an electronic engineer am naturally interested down to the knitty gritty details. It's nice to know we have someone like both yourself and Patrick to answer these questions thanks. The scanguage is a simple obdII/CAN monitor you can simply leave in the obdII port and monitor certain items in realtime, like SOC %, Battery voltage, MPG etc., only four things can be shown in realtime however, but also you can read any codes that come up and also clear them. If the problem is real and not fixed yet the codes will immediately re-appear. It can plug into a genI or a genII prius but I'm not sure about genIII yet but probably does. Not bad for $150. Now we'll see how Mjolinor is doing? I'm very interested in how his quest is going since I will probably be doing the same thing on the 03 in the not too distant future. Thanks for letting me interject. Tom
Couple of weeks, no error codes stored, all is well so basically it was a faulty battery only and under any description should have been replaced under warranty. I have written an email to Vantage Toyota and received no response. Next step is a letter to Toyota UK and if that doesn't work I will send the story to a motoring magazine or something because this is not what I and probably most people, expect from Toyota. Being told it is our responsibility to take the car from one Toyota garage to another when the handbook says don't drive, paying £45 for an incorrect diagnosis that just told us they were not responsible. Probably embarking on a life times task here trying to get them to admit fault but it's fun and that's what life is for.
That's great news. I'm glad it all worked out for you. Yes I too will probably be changing the hv batt eventually in the 03 prius. Not yet though, it's still running pretty strong but it is 7 years old and don't get driven too much, mostly around town. So how much total $ and you replaced both the batt and the batt ecu? Anyway Mjolinor way to go..BTW Happy Holidays to you and yours, Tom
Total £45 for an incorrect diagnosis from Toyota. I didn't replace anyting I just cleaned the battery terminals and bus bars.