DIY hybrid battery rebuild, I did it all and it worked for 20 minutes

You can make balance for all cells so the read will be all the same . Try to ask where they do it ?

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welcome!
sorry, you didn't 'do it all'. it's a long tedious process, if you want to try to do it right, read the many threads here on battery rebuilding.
all the best!

 

This is a separate issue, and a known one where the Combination Meter becomes faulty. Contact Texas Hybrid Batteries (member here) and he can repair, or offer a swap refurb, to fix this problem. It is easily DIY to remove and replace the CM, but a time consuming job. His price is good too.

 

If you're not going to balance the pack, it's best you find 2 matching modules and replace the entire block. That is the best way to go

 

When those lights come on, it means there are specific codes that have been logged to tell you what the trouble is. It could be related to the work you just did, or it could even be something unrelated, that was detected around the same time. Until you read the codes, you just don't know ... you're throwing darts blind at a board with several hundred squares.

-Chap

 

Congratulations, I hope your Napa battery will last a good long while. To keep the knowledge base of recon batteries growing, would you mind posting, from time to time, updates with how it's going?

If you contact Hybrid Texas Batteries (member here), he can advise you on what he requires to program your CM with the correct mileage. There are no other options, AFAIK. It will involve removing and sending to him, or swapping for one he has reconditioned and preset with your mileage. There is a cost for this service.

 

I don't think I'd ever try to rebuild a battery myself.... But I would totally consider one of the aftermarket refurbished batteries with warranty. I saw those for Gen 3's for only like $1600. Seemed like a bargain to me. Hopefully they wont be much more than that, for Gen 4's by the time I might need one.

 

I think in 2019 US "LE" is the base? That level maybe still has Nickel-Metal Hydride battery? Which is more repairable? The Lithium batteries (introduced in 2016, on all but base level) are much less so, almost disposable. The university guy did a deep-dive on the latter, had to drill something out to release the end clamping, and then had a heck of a time getting it back together.

 

First of all you need proper tools if you want to rebuild hybrid battery and they are not cheap. So here are the things you gonna need. TechStream scanner, you can acquire one cheaply by buying the software in eBay for about 20 bucks maybe a bit more now though and download it to your laptop. You have to let them do a remote access so they can download it for you. Then you have to buy the adaptor cable that hook up to laptop USB to the cares DLC (diagnostic link connector). Aka OBD2 connector. Another tool you must have is a mega ohm meter. What this meter does is inject the circuit with high voltage in order to measure any insulation fault. You need to learn to use it properly or you gonna fry some electronic modules. Another tool you must have is a battery internal resistance meter. It is a very useful tool and it can be purchased at Amazon for a decent price. You also gonna need a load tester. Load testing a 7.2V (nominal) NiMH module can be tricky. I use a 100 amp regular lead acid battery load tester since those can also work for 6 volts batter it is close enough. Do not load test too long or you will damage the load tester. A modules voltage should not drop more than one volt as you test them. A bad module usually will dip below 7 volts indicating that it’s weak. Hybrid battery can fail on several different ways. One of the more elusive way it can fail is by having an abnormally high self discharge. As long as you drive the car everyday everything is fine until you park it for a few days then the red triangle pops up. One way to test this is park your car overnight, sometimes it may take several days though. Then get your tech stream scanner and hook it up. Do not turn your car to ready mode though just turn it on without pressing the brake because you don’t want the car to ready and turn the engine and start charging the hybrid battery. Just turn it on but not in Ready mode then with your scanner go to live data and observe the voltage on each block. If there was one module that has an abnormally fast self drain it would show up on that block. It would usually show up as having a voltage much lower than the rest. I usually find them with voltage lower than 7 volts but the rest is like 8 volts. Sometimes they are only half a volt lower than the rest but usually will not set code if only parked for a day or two but will show up as pending code but never throws a code because the car starts charging them as soon as you turn the car ready. So recap here are several way a module can fail. 1) being weak. This defect usually shows up while you are driving or sometimes when car is on and parked and you are running the AC. 2) Leaking battery fluid. They are clear and almost invisible sometimes it can take several days before the code pop up after clearing. The code is shown as P0AA6 and the battery is otherwise strong. The car will also not re start after turning it off. If you disconnect the battery it will reset and you can turn the car on again and drive normally. One last thing make sure you de install all foam padding that are usually on four side corners of the battery. On Prius C they are attached onto the top of battery and are narrow foam and when you rebuild them the ones you replace do not have a foam so you may want to go to Home Depot and buy something almost similar. I usually trim them because the ones in Home Depot is too wide. Newer Camry use them too but are attached to the covers. I think 3 gen prius use them as well if my memory is right but all those foam padding are there for a very important purpose and if you remove them and do not put them back your battery pack will overheat and will fail very quickly. So there you go I think I have not left out anything. A well rebuilt hybrid battery should last at least 6 months, but for the most part they last longer than two years.

 

PS make sure you torque the jut properly with a torque wrench. Google says to torque them at 48 inch pound, but I torque them tighter than that because I feel 48 inch pound is too loose. I would also recommend using new buss bars they are cheap on Amazon for around 20-40 bucks.

I also upgrade them to either LFP (lithium iron phosphate) or Lithium Ion for about 1600 dollars let me know if you are interested otherwise hope my instructions helps you out. My shop is in Houston Tx and it’s called same name as my account except with the number 87. You can find it in google.

 

A torque wrench maybe isn't as important for someone who feels the specified torque isn't right anyway.

Toyota would have chosen the specified torque so as to get a solid, gas-tight, low-resistance connection while minimizing the chance of snapping a stud off a module. There are occasional posts from people who have done that, which made them sad.