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Been sitting for months, HV battery suggestions?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Mark_S, Jul 16, 2022.

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  1. Mark_S

    Mark_S New Member

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    I'm new to Prius and to the forums, although I have been reading a fair bit on here.

    I bought a 2005 Prius with about 143k miles on a tow lot auction. It was sitting for about 4 months from tow till sale and no guess how long before the tow. I have 4 cells showing low charge voltages and higher internal resistance. DrPrius app battery tests says 5% battery life left. Is this more likely to be bad cells that need replacing, or corrosion from sitting for months not being used? Or are there other things that I should check first?

    I tried to record the readings on the DrPrius app, but it gives me a file with a huge number of values for voltages and internal resistances. A typical line is
    10.63,15.309998,15.290009,15.240021,13.890015,13.860016,15.240021,15.230011,13.990021,15.179993,15.01001,15.26001,15.290009,13.990021,15.420013,19,19,19,21,21,19,19,21,19,19,19,19,21,19,94.33795,96.40796,93.941956,100.0,1.79,2.2000122,0.0,07/16/2022 06:52:52 PM
    The 15. numbers are cell voltages, the 13. are bad cells voltages, the 19s and 21s at the end are internal resistances, the 21s being the bad cells.
     
    #1 Mark_S, Jul 16, 2022
  2. bisco

    bisco cookie crumbler

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    i ould open the battery, clean everything up and load test all the modules. the easiest thing would be to replace them all with new, but if you're trying to do it on the cheap, you could gothrough the whole rebuilding process.
    in the end though, you have 17 year old modules that have sat awhile
     
    #2 bisco, Jul 17, 2022
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  3. JohnPrius3005

    JohnPrius3005 Active Member

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    If it starts and drives, start and drive it. ;-) Any problems will show up sooner or later. I've left my cars for many months and the HV bats are fine.
     
    #3 JohnPrius3005, Jul 17, 2022
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  4. mr_guy_mann

    mr_guy_mann Senior Member

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    Take a screenshot of the Dr Prius app data and post it. Sounds like yes, the HV battery is bad. What you do about it depends on your budget, capability - skillset, attitude, time, tooling, & workspace.

    Use the search function to read up on DIY module replacement vs "refurbished" batteries vs new batteries.

    Posted via the PriusChat mobile app.
     
    #4 mr_guy_mann, Jul 18, 2022
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