Hybrid battery - how bout just changing bad cells without "reconditioning"?

You're better off buying a complete used battery and replace the one you have. The way you're thinking about doing it, it won't last long and with all the work involved in doing it, it might just be worthwhile to do it correctly the first time or don't do it at all. It'll be a waste of time and the problem will come back again real soon

 

The major problem is the stuck pressure release valves in each module pushing the electrolyte out through the terminal seals. The electrolyte needs to be topped up, the pressure valves feed and the module links cleaned and voltage sense wire harness replaced .... along with checking the pin stick out in the battery computer module ..... all in this post here https://priuschat.com/posts/3551878/ How to top up the electrolyte, the mix ration and how to release the pressure valves is in a thread about rehydrating battery modules Re-hydrating the battery modules. | PriusChat

T1 Terry

 

How far do you want to move the car? If it is not very far, you should get able to do it with the hybrid battery that is in the car.

 

some have had good luck just replacing bad modules with good, but it's a minority for sure.
there are too many factors involving the remaining modules to know if it will last very long or not.
if you just want to move the car, it should work, but won't disconnecting the 12v to reset the codes do the same thing?

 

I always explain that if it's the first bad module on a pack that's never had a problem before you can buy a high quality replacement module for $35 and put it in and get lucky for a year. Plenty of people have done that. Of course myself and others sometimes barely get a few miles down the road before warning light come back on doing that.

As in each module you replace the more problematic the pack is going to get. However if you have access to lots of modules and you recondition and test them and match up modules of similar performance you can get several years from a rebuilt pack.

 

This is the ABSOLUTE wrong way to go. If you have a HV battery that is basically original or 'unrefurbished' or has a ton of miles on it, and now has only one bad module, the last thing you want to do is replace it with 1 HIGH quality module. You want to replace it with a mediocre module, somewhere in the 5400 mah range, so it fits right into the average condition of the other 27 modules. The last thing you want is one module that's in excellent condition where the computer is comparing it to a bunch of not so excellent modules. You're inviting it to throw a code asap, because now the lower capacity (but still good) modules/blocks look like crap compared to the block with the "new" one.

Yes, your idea can work very well, if you apply some common sense and understand how the battery voltage monitoring and faulting work. The module you install merely needs to be healthy, with no individual failing cell inside. The Dorman batteries are actually typically very decent quality, even including nickel plated busbars and the ecus have always been in great shape. I've repaired a handful that just needed one module replaced and then went on to serve years of additional faultless driving. If I need to repair a 'rebuilt' battery, I'm a bit happier when I find out it's a Dorman. In YOUR situation, with your desired outcome, that's the one I would repair and keep for my car.
Do your simple repair, verify the condition of the wire harness and ECU socket. If they need repair, then there's going to be some additional expense, or you may be able to switch parts around between the 2 batteries to make a good one.

Good luck!!

 

Weigh the modules, especially those from 2004 to 2007. If their weight is ~ 1030 grams, you should not expect them to work for a long time. By restoring their capacity, it will be restored, but it will also be lost very quickly after installing the battery in your prius.

 

WOW. I don't know what else to say about that Dorman. I find it hard to believe that Dorman built that battery with the temp sensors on top of the modules instead of underneath where they belong. It almost looks like they spliced in Gen 3 thermistors (which are top mounted in the wells) to the Gen 2 temp harness. If so, that is still totally unsatisfactory. The Gen 2 supplies cooling air from the top, and should have bottom mounted sensors since that is where the higher temps will be. The Gen 3 supplies cooling air from the bottom and has the temp sensors on the top. That setup in your photos is jacked up.

Actually, those temp sensors don't even look like Gen 3s. The gen 3s actually clip onto the plastic tabs on each side of the well.

 

what should a good weight be?

 

Any company that remanufacturers these batteries (other than Toyota themselves at one point), will not have the quality control to have consistently good product. Their job is just to put modules back together and sell them back out, fast turnover is the key to their business model.

 

1035 to over 1040 grams. The higher, the better.
But the weight does not guarantee that the module will be good. The mileage can be 250k miles on it. I will soon weigh 2015 modules, with 270k miles.

 

Here is the weight example of the modules that were pulled from a wrecked 2012 Prius V with 144k miles.

 

Keep in mind that there is a newer type of nimh modules weighing 1000 grams (not 1040 grams), and their actual weight may be up to 1016 grams. 1016 grams can also be found on modules from Panasonic, on gen 2 prius. This is already trash. Usually, the weight does not drop below 1020 grams on Panasonic modules, the triangle lights up much sooner.

 

That complicates things alot... Any chance someone knows the first known date of manufacture of the lighter NiMH modules?

 

That makes no sense... Toyota only uses brand new modules... There's zero quality control for used modules with Toyota because they profit off of any possible excuse to sell the customer a brand new pack.

I think it would be more accurate to say that professional battery rebuilders with 3 and sometimes 4 year warranties have spent tens of thousands of dollars on lab grade electronic gear to maximize quality control, whereas all us hobby charger folks on PriusChat don't have that higher level of quality control.