Hybrid Battery Reconditioning 2009 Prius

Hi all. I've been a member of this forum for about 11 minutes so far. I have 2009 prius with 175,000 miles on it. I'm the second owner. First owner put 125,000 on it. The hybrid battery died at 170,000.

Thanks to Youtube I tore the hybrid battery apart, found the lowest module, around 6.5, and replaced it. I was low on time and money and against advice I didn't do anything else. I put the car back together without rebalancing the battery or anything else. As predicted it didn't last long. I got about 5,000 miles out of it before I received the triangle of death again.

I have the battery apart again and a different module has triggered the triangle of death. I've found it. It's also around 6.5.

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Questions: What modules are worth reconditioning? I'm going to buy a unit to recondition the modules. Can I recondition one that reads 6.5? 6.7? 7.1? How low is too low?

It is my understanding that all the modules need to be "similar" in voltage. What is the acceptable variance? 0.3?

Thanks!

 

Thanks for the responses. I have, I believe, everything necessary to begin to test and recondition my Prius battery. My question is, what are the tolerances or number range that a module is considered good. My understanding is that on the discharge cycle you want to get the battery to 5,000 mAh and on the charge cycle you want to get it to 7,500 mAh.

If you can't get a battery to 5,000 mAh on the discharge cycle do you consider it dead?

If you can't get the battery to 7,500 mAh on the charge cycle do you consider it dead? How low can it be and still be considered reconditioned and useable? 6,000 mAh?

 

Thanks! This helps a lot. I laughed when you said you wouldn't do it again. I can see how it's a lot of work. I would be thrilled if I could get another 50,000 miles out of this car. Its only at 175,000 so I feel like there is life left in the old girl.

 

So I have just begun to my first real attempt at reconditioning my battery.

I tested each battery module and here are the readings.

Module 21 is low at 6.21, so I imagine it will need to be replaced.

Module 15 is high at 7.87, because I swapped it out 5,000 miles ago with a used one from eBay without really knowing what I was doing.

My question, for those who've done this, is what does this data tell you?

Or will I not really know the "health" of my modules until I've attempted to recondition them?

Thanks!