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do I need a new hybrid battery or not ?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Rahem Abdennadher, Mar 26, 2020.

  1. Rahem Abdennadher

    Rahem Abdennadher New Member

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    I own a 2005 Toyota Prius. it is driven 253k miles. a week ago that red triangle, the check engine light, a VSC light, and what I think is the ABS light turned on in the dashboard. I took my car to a mechanic, and he used an obd reader and then told that I need to change the hybrid battery. well, I can't afford a new battery now, so I took out the hybrid battery by myself, and tested every cell in it. all the cells generate >7.5 volts except one that generates 6.4 volts. so I changed that cell with a new one that generates 7.5 volts, and put the battery back in the car. after that I went for a ride to test the car. every was fine for 20 miles, no notification light on, the drive feels normal, and no strange noises at all, with 38 mpg average. all of the sudden the same 4 notification lights turned on again, and the fan of the hybrid battery went on also, and the drive started feeling strange. I parked the car for 12 hours and then went to check on it again, now as soon as I turn the engine on, the hybrid battery fan starts working and the 4 notification lights also.
     
  2. bisco

    bisco cookie crumbler

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    you can keep rebuilding it. if you want to do it right, it gets more technical, and takes more time. plenty of threads here with details and pics.

    otherwise, you're going to keep pulling the battery to replace bad modules.

    you can get a new one for $1,600.
     
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  3. Rahem Abdennadher

    Rahem Abdennadher New Member

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    Hi
    do you think the problem can be caused by the cooling system of the battery and not the battery itself.
    what is the right and cheap way of rebuilding a battery or is it just changing bad cell until the red triangle stops from showing up.
    thank you.
     
  4. prius_deep

    prius_deep Member

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    when you took out the battery did you check the hybrid battery fan -made sure it was not clogged with [pet] hair, or 'dirt'.
     
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  5. prius_deep

    prius_deep Member

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  6. Prodigyplace

    Prodigyplace Senior Member

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    Did you mean to say You can build a new one for $1600? I think new Toyota packs cost more than that.
     
  7. chronon

    chronon Active Member

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    This does sound like when the mistake of reverse block polarity connection occurrs (like when u pull out some modules to refurd individually with discharge/charge cycles) ... or modules that have depleted so far that a cell inside has flipped polarity ---

    a good guy on here helped me out last year, with phone call , telling me to get the app 'Torque' -- with this $ 5 app, u add in the voltage widgets for each block and u can watch the V in real time (no more case removal and DVM hands on pain and misuery(which u wouldnt want to do when car is running any way)) - of course u need a dongle -- bluetooth / wifi -- android is preferable phone to install on and i think the wifi was the better protocal (those dongles are around $5 as well)
     
  8. Albert Barbuto

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    I also own a 2005, with the original battery. Vehicle has 60k miles, so it has less use than yours. Spend $5 and get the Torque Pro app. You will also need a Bluetooth adapter. I purchased the Panlong mini OBDll. Cost $12 eBay shipped. Works perfect.

    I like to back up a small hill right down the street from where I live. A Canon Powershot in movie mode gathers all the data. Notice in the included pic the battery is seeing a 54 amp load. That's a good sized load. Tests all the modules at once. A weak module/s will show up ASAP. Please be aware that the voltage blocks are for a "pair" of modules. One or both may be weak.
     

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    bisco likes this.