My experience with a mobile battery repair in central California

SO.....you paid $400 for only ONE new cell.
NOT a good deal in my book.

The other cells are the same age and likely will fail soon too......like a matter of months or weeks.
A LOT of owners who start down that path are soon sorry that they did because it turns into a continuous hassle.

Good luck. You likely will need it.

 

I agree with Sam, 4 repairs like that and you will have paid the cost of a completely new battery kit from newpriusbatteries.com

So, start saving up for that now.

 

congrats!
did mike talk to you about what all the risks and possibilities are as you head down the road?

all the best!

 

Another wack a mole repair here. Sometimes its even the customers that would desperately forced you to just do whatever it takes for me to get my car "fixed today", not minding the tediousness of the exercise. I usually explained upfront to my clients about jobs like these. If they can't dropped off the car for the required duration, I'm not going to be blamed for any failures in the future.

 

@Pro-289

I'm glad you were able to get the car fixed. Sometimes you have to do what you have to do. Unfortunately, anyone who comes to you and swaps one module and calls it good, isn't really doing you any favors, other than getting your car back on the road "today".

When your car was new, you could think of your HV battery as being made of 28 brand new "D" cell batteries. As it gets miles and wear and tear, the individual D cell batteries wear and age differently. They're never exactly the same, even when new. As they age, the individual capacities change, but not by the same amount. After several years and a 100k miles, you now may have 5 "D" cell batteries, 10 "C" cell batteries, 7 "AA" size batteries, 4 "AAA" size batteries and 2 "CR2032" cell batteries (and one of the 2032 has failed). The problem you're going to have, is that unless he brought some 'real' test equipment with him to test each module you still have the other 2032 cell and the AAA cells in the battery waiting to fail, which could be next week or could be next year.

Here's an example of a HV battery removed from a 2007 Prius with 143k miles. The battery was replaced. It was removed from the car and about 3 days later, placed on my workbench to measure the energy remaining in each individual module. This is my best indicator for checking the health of a replaced battery. It gives me a clear view of how the battery was balanced (or actually out of balance) when it finally failed and coded out.

The column label 'first discharge' is a measurement of how many units of energy remained in that module. Kind of like how many pennies in a jar. In this example, it was module 9 that was causing the car to code out. Over the next couple days, modules 11 and 13 had enough self discharge problems that they also now show up very easily.

You can see there were 3 modules (in red) that could be easily identified as being bad just by using a voltmeter. So he found one that was similar to these 3 and replaced it. The question is, did he find the other 3 in yellow, that are destined to fail very soon?

 

Yep, it is not a good situation for poster to be in. $400 here, $500 there, and after 3 fails money spent could get the entire repair done.

 

Well warnings given, warnings received.
I normally would pile on with continued illumination that singular cell replacement rarely seems to be a long lasting solution BUT....

I'm not going to debate or disparage the actions of a OP that sends messages from his Atari 400. That's a trump card there. Good luck with your mobile battery repair.

 

Single module replacement works for those who understand what they are getting.

It is not ok if the repair person pretends like it is "just as good as a new battery pack". It ain't.

Sometimes putting a bandaid on a bleeding aorta keeps you alive, and you are satisfied with that. You know it won't last, and it could fail at any time. As long as you are aware of the situation is what is important.

 

OK, so your back to running well. Excellent! Let's keep it that way, by doing a little work, and barely spending any money.

1) Purchase Torque Pro for $5.

2) Use your OBD adapter.

3) Back up a small hill, or accelerate on the level to put a "real" load on the entire pack. We are talking 50-60 amps.


You will quickly see what pair of modules are weak. Work on these modules while the pack is in the car. Cycling will bring them back to life. Stubborn modules may need to be re-hydrated.

 

Guess I'm number 5 on that list....What a shame. That kind of hurts my feelings... And here I was, even stating that we all sometimes gotta do what we gotta do, and then providing some real data as to what to look out for.

Grumpy? Naw, not really.

Old....well, I suppose I'm getting there day by day. My best days are probably behind me and I've probably forgotten more about a Gen 2 Prius battery than most people will ever learn.

work for a 'battery shop'?..not really unless you consider I'm a one man show with a side gig specializing in building Gen 2 batteries using Gen 3 and Gen 4 modules from late model wrecks and that I've installed my batteries for a few dozen forum members. (How's that for a run-on?)

Have somewhere around 1500 modules 2003-2017 on the shelf taking up space? Yup

I think I'll go practice my grumpy skills on the wife and kid...

In the meantime...There are many members able to provide advice on Gen 2s. There are several very knowledgeable members who can provide very sound advice irt HV battery and HV system issues. Your dilemma is just figuring out what to listen to...…...

 

thanks for sharing your experience. Could you recommend a good shop in the central cali for priii? I'm looking ahead to when my 25k free service expires with the dealer. also, would want to get my transmission fluid done at some point, and i've read dealers are taught that shouldn't be replaced so they have issues with that. of course wouldn't mind saving some cash.

 

Pro-289,
You've got the right idea to prepare for another failure.

You certainly could do the work yourself if you put in the time watching videos etc.

I'm always happy to sell modules to folks and help them through the repair of they need it. It won't last as long as a new pack, but it may just get you by enough for what you need.

 

Clean up your act please.
Jesus doesn't care about your battery or the banter that goes on here.

AND.....while your information might be valuable, you seem to think that EVERYBODY who owns a Prius should be capable of and interested in doing something similar to what you did.

NEWS FLASH: The VAST majority of owners have no ability or interest in messing with the battery themselves.

 

I’m in the DFW area. Had an issue with check engine light indicating multiple cells going bad. Went with HBRepairOK who came down and swapped the battery for $750. He explained to me rebalancing and load testing on cells. Battery is still working 1.5 years later (knock on wood).