Augh!! P3000, P0A80, P3021, C1259 on an '07

I have 97k on it. Still under warranty until October 2019

 

I thought you were much further along on the disassembly. The 4 bolts I thought you were referring to were the module clamping bolts, next to the venting tubes. I didn't know you mean the mounting bolts to the car.

Anyways, it's on the bench. Doesn't look too bad. Remove the bus bars so it can be handled safely. Remove all the copper bus bars and soak those in vinegar, that'll get rid of the corrosion before you reinstall back on the car.

The pack looks original, all the side markings are similar. I don't think anything has been replaced on a 2007 with so few miles

 

I took it off final charge at 7am and came back and drove it at lunch. Nope, no fluctuations and it retained full blue bars much longer.

I realized another way to determine falling battery performance on mine: the ability (or lack thereof) to maintain an EV glide at around 40mph. After the reconditioning treatment, it can now go for long stretches on a level road in EV whereas before it was constantly going in/out or just flat would not maintain EV at speeds approaching the 42mph EV limit.

 

Is it possible to remove the battery cover safely while the battery is stilll bolted in the car to check for corrosion or does the entire battery have to come out for that please?

 

Battery does not need to come out to "look". But you should remove the battery if you need to clean them. You want to have enough space to move around safely.

But it's possible to do everything while the pack is in the car. If you're careful enough, it can be done

 

How often are you reconditioning the pack?

 

Twice per year: jan1 and july 4th has been my schedule so, obviously, this one came early when I notice the fluctuations last friday. We only put about 5k miles on it since getting the grid charger last July 4th. I kick myself in the butt for not putting it on techstream to see which module(s) were acting up before starting this reconditioning. arrrrgh!

Anyways, I have a dilemma. A week from now both my son (the other driver) and I will be gone out of state for 2+ weeks. I'll plead with the wife to drive it as much as possible but I know she'll take it out once or twice on a short errand at most.

 

Discharging to even 29 volts seems pretty low, and there is no guaranty that you didn't reverse bias a cell.

The voltage on the weakest cell was: 29 - (sum of all other cell voltages), and there is absolutely no way of knowing for certain that this evaluates to a positive number.

Given that the pack was a rebuilt one, so possibly not all that well balanced or matched to start with, I think a reversed cell is more likely the real problem rather than driving it too soon.

BTW. What is the recommend discharge level for the pack discharger? I've never done it, but thought that the normal levels where more like about 150V down to 70V, depending how deep a discharge you wanted to risk.

 

I agree the battery cell probably died from a reverse charge. 29v = about 1v per module of 6 cells.

Although the instructions from prolong says to discharge all the way down to 17v, I don't feel that's a safe level to do multiple times. I tend to stop at 134v on reconditioning.

Those of you that have the prolong system, see if you notice the difference doing 3 discharges down to 134v and not below. You'll be surprised the results will be just as good without the added danger of reverse charging by going too low on the discharge.

Remember Toyota limits the battery usage to 40 percent on the low and 80 percent on the high. That's to give the battery a 10 year life. If you continuously go outside that range, you'll end up killing your battery prematurely.

Just my opinion.......

 

Thanks JC.

FYI- I bought a discharger months ago the old school 2 light bulb system and was going to do a discharge over the Holiday weekend also but found in my wisdom I had misplaced the discharger cable. I called Hybrid and was told my already installed charger cable can be modified by removing the inline diode and installing a 3 amp fuse in its place. Then it becomes a charger/discharger cable.

 

JC can 134 volts be achieved by one set of light bulbs or do you still have to change bulbs to get there please?

 

I first start off charging the battery for 12 hours. I know others have suggested charging 24 hours before beginning a discharge cycle. But I feel that's not necessary as you're working with a battery that's above 210v in the car. Only time I charge 24 hours is from a deep discharge 134v or lower. I try not to overcharge the battery as much as possible.

I normally use 100w bulbs down to around 201v, then switch to 60w down to 180v, then 25w going further. Prolong suggests you can use 60w down to 140v. But I have plenty of time and want to use a low current so I reduce the risk of reverse charge. 25w takes a little longer, but that's only 2 or 3 hours more. No biggie.

I don't have the intelligent discharger so I usually split my discharge into 2 days. First day would be around 4 hours going from full charge down to 201v (stay within nominal range of car specs).

2nd day I do the deep discharge down to 134v (if you miss this mark and go a little lower, it's no big deal). You'll know the pack is nearing empty at this point because your 25w bulbs are starting to get pretty dim.

I do this so I don't waste 8+ hours of my day discharging and looking at that battery. I usually start after dinner and stop by bedtime. Charge back up at night time while I sleep.

I do the same on charging back up. Split into 2 days, only charging while I sleep. 9 hours at a time. Final charge would be longer at 12 hours at a time.

I have a set up where I do this inside or outside the car. I find it easier outside the car and I have more flexibility. I use the same setup, buying an extra battery fan from a wrecked prius. So there's no difference either way.

All this is just my experience and my opinion of how things work. I'm not a battery pro but an extreme hobbyist.

 

Thanks JC & Jerry for you help. Going for it this weekend.