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Anyone else having 12V battery issues?

Discussion in 'Gen 1 Prius Plug-in 2012-2015' started by LurkAzusa, Sep 15, 2012.

  1. Easy Rider

    Easy Rider Active Member

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    Actually most inexpensive solar panels are of such a low capacity that there is not even a remote danger of over-charging.......unless maybe connected to a really tiny battery, like in a cell phone maybe.
     
  2. GregP507

    GregP507 Senior Member

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    Some are regulated; some aren't, and if they have enough wattage to do any good, they also have enough to damage the battery over a long period of time. In any case, most 12 V sockets aren't connected to the battery when the car is stopped.
     
  3. Steve42

    Steve42 New Member

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    Having the same problem and I've been unable to jump the car despite carefully following the instructions. Is there any special technique to doing this jump other than hooking the clamps to the proper locations? Do I need to wait a few minutes to let the system boot up before trying to turn it on? Also, if I'm unable to jump the car will a trickle charger be of much help?
     
  4. GregP507

    GregP507 Senior Member

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    Have you found the special jumping terminal on the fuse-box under the hood?
     
  5. Tracksyde

    Tracksyde Member

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    I had a regular battery charger on it (red clip on the positive terminal in the fuse box and black clip on the engine ground). The battery charger had some quick start setting, a 1 or 2 amp setting, and a 10 amp setting. When I initially started the car, I had it on the quick start setting. When I opened the door, the interior lights were on but they seemed weak, kinda dim. But when I hit Start, the car booted up as usual.

    However, after getting the car started, letting it run for a bit and driving it around some, it wasnt enough to get the battery charged up (it was dead again the following morning). So the next day, I put it back on the charger and on the 10A setting and left it for about 3-4 hours. Its been fine since (even after another period of sitting in the driveway unused for 3 days).

    I'll be out of town for 5-6 days soon. So we'll see how the stock 12V battery handles the downtime. If its dead when I get back, I'll put in the Optima. If its still alive when I get back, I'll procrastinate some more and wait until I have some free time before switching out the stock battery.
     
  6. GregP507

    GregP507 Senior Member

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    This may help or it may not. If the interior lights seem dim, it could be a poor connection from the battery, or just a bad battery. Running the engine doesn't have the same effect of charging the battery, as in a regular car. The auxiliary battery is charged through a voltage converter with power from the main traction battery. It's unlikely that the power required to charge the aux battery would put much drain on the main battery, therefore it wouldn't require running the engine, and which would probably not have much overall effect anyway.
     
  7. Tracksyde

    Tracksyde Member

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    Well, in my case, I didnt have any EV range left. So when the car did turn on, the engine started. But leaving the car on/ready and even driving it around for a bit wasnt enough to charge up the 12V battery so that it would at least last through the night. I read other people here mention only needing the car to be on for a "few minutes" and having the traction battery charge up the 12V. But in my case, that wasnt enough (or the generally accepted meaning of "a few minutes" isnt the same as mine)
     
  8. Easy Rider 2

    Easy Rider 2 Senior Member

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    Being sure it is fully charged before you leave, like charging it at 2 amps overnight, will help a LOT......but your story sounds like your 12 V is on borrowed time already and needs to be replaced.

    And if it is common to have periods of more than 3 days unused, a ~$25 automatic tender type charger would be a good investment........no matter what kind of new battery you put in there.
     
  9. GregP507

    GregP507 Senior Member

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    Couple of things. The EV range is only a minor part of the traction battery. Think of it as surplus power, beyond what the hybrid system needs to function. When the EV range is zero, there's still plenty of power left in the hybrid battery. The aux battery doesn't need much power to turn on the system, even a partial charge will work. Once the system is turned on, the aux battery is being charged, even if the engine is off.
     
  10. Astolat

    Astolat Member

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    Correct me if I'm wrong, but I don't think anyone has posted here or on other threads with a problem from 3 days of non-use (even repeatedly) unless
    a) they have accidentally left a light on; or
    b) there is good reason to believe the battery has been damaged by deep discharge, either on the way over on the ship or on the dealer's forecourt.

    If it really was necessary to arrange for a trickle charge in those situations, I'd say Toyota had a serious problem, but I don't think the evidence points to that yet?
     
    bisco likes this.
  11. GregP507

    GregP507 Senior Member

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    As before, I recommend that a good mechanic should be able to trace a current leak, if that's the cause of the battery discharging. Also, a damaged battery can discharge itself, therefore a new battery would be necessary. Either way, the dealer should be able to resolve this.

    Trickle-charging is a band-aid fix for the symptom, not a solution to the problem, and it's not even a good band-aid fix. A battery-maintainer (battery-tender) will not damage the battery over a long period of time, as a trickle-charger could.
     
  12. Easy Rider 2

    Easy Rider 2 Senior Member

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    I didn't say it was REQUIRED but I do think it is a good idea, given that in most cases you really have no idea what the general health of the battery IS. Or what SOC it is being left at when the vehicle is powered down. Replace 3 days with 7 days; pick a number. General experience says that there IS a number but it varies some from one owner to another.

    It is insurance. Nobody really needs insurance but it's still a good idea in most cases.

    And lastly, a trickle charger is NOT recommended. It needs to be an automatic tender type.