2007 Prius Hybrid Pack Rebuild

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by gallanbile, Apr 10, 2024.

  1. gallanbile

    gallanbile New Member

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    I'm in the middle of cycling through my pack and have a question about the rebuilding process. I've found two options that people have done but I'm not sure which one is better.

    Example 1 : Pair two modules with the same capacity together and put the highest blocks in the middle
    Example 2 : Pair a weak and strong module together so the block capacity is the same throughout the pack and put the same cap blocks in the middle

    Some extra info about the rebuild: About half the pack is bad (<3000). Bad luck on my part as I've seen other rebuilds only replace ~5-7 modules. OEM packs ~$2.8k and reconditions are $7-800 in my area. I probably should have went with a recondition if I knew they were using good modules (>5000) but I didn't know much before starting the rebuild.
     
  2. TMR-JWAP

    TMR-JWAP Senior Member

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    Can you describe what method you're using for cycling/testing these modules?
     
  3. gallanbile

    gallanbile New Member

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    I'm using a cq3 charger. From all the videos/posts about rebuilding, I was hoping that my cells would be 5000+ but only 3 hit that number. I've decided to rebuild the pack with any modules that hit 4k+. I haven't finished cycling all my modules yet but it doesn't look great.

    So back to the rebuilding, I can either arrange the modules so the end blocks are ~8k and the middle will be ~10k or I can pair weak/strong to make each block around ~9k capacity.
     
  4. avoice217

    avoice217 Member

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    Hey man so I have the exact same charger. So the whole idea is to try and 'rebuild' each module to as much power as they can hold. Just because you're hoping to hit the 5000 mAh number doesn't exactly mean that this will happen. There's videos on Youtube about people saying that some of their modules only reach anywhere from 3000-4200 mAh (bare in mind that I'm just giving average numbers). Overall, the two most important thing is the mAh, but also the beginning voltage. If any module is below 7v, then you're more than likely not gonna get the mAh above 1000 (like in my case).

    Also there's videos out there saying that just like any rechargeable batteries, they only have a finite cycle and each prius battery pack is a unique story. Unfortunately mine is one of the worst ones in that I had all bad cells. At least I learned my lesson and know where to keep an eye out in the future when it comes to trying to keep them alive longer.

    On a side note, I'm not really understand where you're getting 8k-10k from. The maximum recommended capacity for each module is 7500 mAh. It shouldn't go above that or you risk damaging the cell (at least that's what I've been told).
     
  5. gallanbile

    gallanbile New Member

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    Thanks for the input. Each block is made up of 2 modules. The 8-10k are the discharge number from both modules. The 7500mah you're referring to is probably the charge. I have my charger set to 7200 as a safety precaution but will bump it up to 7700 then 8200 if needed.
     
  6. gallanbile

    gallanbile New Member

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    Update: I have about 10 that made the 4k+ mark and 8 that are in the maybe (3k). I've only run 3 cycles as I've found that running more doesn't always produce results and it takes time. I will run more cycles once I finish the pack.

    I've decided to pair the strongest modules together and place them in the middle.