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12V battery monitoring

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by friz, May 15, 2021.

  1. friz

    friz Junior Member

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    I purchased an optima 12V battery for my 2010 Prius in July of 2017. It recently drained for the 2nd time since then and I could not start the car. I tried to charge the battery as I did the first time but it wouldn't take it. I called the optima's help line and followed the instructions for charging a battery that was completely dead. Worked like a charm. Put the battery back in the Prius and all is well again. My question is this. Is there an easy DIY way to monitor the battery so I can charge it when it's getting low on voltage? Thanks.
     
  2. Grit

    Grit Senior Member

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    I was thinking along the lines of finding out if there is a parasitic power draw or door not closed all the way rather than keep charging a battery. That’s like fighting a fire by hosing the flame rather than putting out the source that is burning.

    If you really want a challenge, buy a multimeter and measure the voltage when you have the time. But batteries aren’t supposed to require any charging unless you only drive your car once a week.
     
  3. Mendel Leisk

    Mendel Leisk Senior Member

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    Check it periodically with something like Solar BA9.

    Is your usage sporadic; the car frequently sits for days? Say due to COVID? If so, you should look into smart chargers, keep it connected during the hiatus. If that’s not practical, consider just disconnecting the neg cable: it’s a pain and you’ll lose memories, but it’s the constant low-level drain and that kills it.
     
  4. ttou68

    ttou68 Active Member

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    If vehical is parked outside, has anyone tried a 12V solar charger?
    I have one, the downside is that my doors won't lock when it plugged-in...

    Posted via the PriusChat mobile app.
     
  5. AzusaPrius

    AzusaPrius Senior Member

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    @ttou68

    Wow nice solar charger.
    You should post a link to it.

    I do not need it because I tapped into the factory solar panel and it is charging my 12v just fine, but I had to lower the voltage because too much keeps the ECU's on.

    That is why it seems you cant lock the doors, you just have to keep pressing the lock button but mainly lower the voltage from you solar panel to the 12v then you will be able to lock the doors again.

    http://www.RedBullet.net

    http://www.ProjectLithium.com

    http://www.Pulstar.com

    http://www.PlugOutPower.com
     
  6. ttou68

    ttou68 Active Member

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    Nice, I would definitely attempt solar roof mod when I find one equipped with..

    I've had it from very long time ago, so I don't have a link but Amazon have plenty of choices.. 20210518_171956.jpeg 20210518_171935.jpeg

    Posted via the PriusChat mobile app.