battery rebuild basic questions

I know this topic has been discussed ad nauseam here, so please pardon my repitition. Storms have my internet down and I can't see well enough to read through all of them. However, I've already read many before.

I have two batteries that were throwing codes. I don't recall which codes. I replaced them in those cars and would now like to see if one or both of these can be rebuilt.

I've taken the cover off one and the bus bar caps so I could check voltages. They all seem usable - one was at 6.84v, one at 7.74v, and one at 7.8v. All the rest were between 7.3 and 7.5, most right at 7.49. I think I see jelly around one of the bus bars, along most of the terminals.

I'm thinking that this one has a leakage issue and not dead modules. Is there an easy way to check the bus bars for diagnostic purposes? And how about around I clean everything up and reassemble - can I check to see if I fixed the problem without reinstalling the battery in the car?

 

Thanks, Ammdb. That jelly does look very consistently applied, like it was intentional. That sounds good. If I get another module that is already within that same 7.5v range, can I just do a straight swap, or do I need to balance charge the pack?

I expect I have a decision to make - the other battery is probably almost all good cells too. I'm thinking I'm better off to fix both by buying some new modules, rather than scavenge one just for a single module.

If I'm reading older posts correctly, I could also drain/recharge that 6.84 cell several times and it might come back?

 

Thanks. Yes, I've read some of those threads, but didn't want to try to research using my phone. Maybe I keep the second battery as spares. Haven't checked it yet, but I only drove it <100m after the first time it flashed a triangle, so I'm think it should have mostly good modules.

I haven't bought packs from Toyota, but I've bought from Dorman and BestHybrid, and both performed well. Lately, I've been scavenging from wrecked Prii. It's not that hard to replace the battery. I can do a complete swap, in/out, in a little over an hour. The batteries are heavy, but just to get them out of the car and onto my dolly isn't too much. I've carried them from one car to the other by myself. Good exercise.

Everything is a matter of time, lol. Right now, I only need two more batteries, so if I got both these to work, I'd be good. But, between all the leftover parts I have, I can fix some cars for free, so I got my eye on another one right now. It may need a battery too.

Any suggestions on my other question - if I do swap a good module in, can I reassemble and test to confirm it's fixed without installing it in the car? Swapping them isn't hard, and it's not too heavy, and it's good exercise, but I'm not a glutton for punishment.

 

I aim for FREE batteries and have managed to get several. These two didn't cost anything. Of course, nothing is free, I do have to run around, and do some work, and take some risk, but I've not been burned yet. I'd just like to use these up rather than toss them. I already have two old battery cores sitting outside in the rain.

That doesn't quite work. I dare say there's not a single Gen 1 left running off the original battery at this point. They've all been replaced by now, maybe more than once; and, you can't tell by looking, that I know of, how old the battery is, and you get no info on a wrecked auction car.

It's a dice roll; however, you'd rather get one out of a wrecked car than a non-running car that looks nice. It is almost a certainty (you can usually tell how the wreck occurred) that the car was running/driving at the time of the wreck. As long as the wreck didn't hit the battery, it should be good. From the tow truck to the auction usually takes a couple of months. The ones I've procured have displayed the lowest level when I first turn the key on, but all have started and charged right back up in a few minutes.

 

I just opened up my second battery and it's voltage is lower across all the modules, which I assume is normal since it's been sitting up about 4 months baking in our 100+ degree summer. Most of its' cells are 6.9v-7.3v, most of those, 7.1v-7.2v. It does have one that's 7.4v, like the one I need in the other battery. It also has 4 that are lower, 6.0v-6.5v.

So y'all know, I'm losing it a bit in my old age - harder for me to research all this stuff, and I am hopelessly helpless with electronics. I understand that voltage isn't capacity, so I really haven't learned anything about how long these batteries will last. I'm thinking, however, that as long as all the modules are within the acceptable voltage range, and all within (?) ~.3v, it will work. If so, then I will get an alert that the capacity is/getting low if my gas mileage sucks.

I think I can get that with the first battery, by swapping in the one 7.4 module in this second battery. So, I'm going to give that a try.

The second battery...it appears that most of the modules have some life left in them. Don't know that I want to mess with all that though. Maybe I just sell them as modules on Ebay? probably save the metal box and ECUs for spares. Overall I need to be getting rid of all these parts and cars, lol. However I got enough parts to fix one or two others for free - if I see ones that match up with my parts.