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12V Battery Drain Causes?

Discussion in 'Prius c Care, Maintenance and Troubleshooting' started by ArcticPriusC, Feb 9, 2018.

  1. Mendel Leisk

    Mendel Leisk Senior Member

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    Your measurement seems high. On our 2010 Prius I measured parasitic drain under 20 milliamperes, with sporadic spikes to around 40.
     
  2. Mike4kz

    Mike4kz Junior Member

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    Yeah... The only thing - I have a weird amperemeter... Will try another one today, if that one actually screws up a number of digits...

    PS. Yeah. These readings were correct. Got another multimeter with full display - drain gets between 95 and 130 mA. That's really high...

    Update... Based on other readings, I decided to start removing fuses (under the hood) one-by-one. When I removed the fuse for "DOME", the drain dropped from 100 mA down to about 40mA. Removing two fuses called ECU dropped it even more (down to 7-8 mA), but I think it's not a good idea.

    However, I found one "caveat" of this... Now I got "Slip indicator" on all the time. When I put a fuse back, the dome light turns on, "slip warning" turns off, but the drain gets back to 100-130 mA.

    And yes, I checked all lights, they are off when the doors closed. However... thinking back... the light in my trunk is always off. I have to do some more testings if there is anything with either trunk door switch failed, or bulb went off (or shorted)...
     
    #22 Mike4kz, May 3, 2021
    Last edited: May 3, 2021
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  3. bisco

    bisco cookie crumbler

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    has the new battery drained yet?
     
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  4. Mike4kz

    Mike4kz Junior Member

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    No. It is a "higher capacity" battery. And with 120-130 mA it will take a while to drain it completely. However, I'm trying to understand what's going on (and what happened)... As I said, removing the DOME fuse drops drain for about 80-90 mA...
     
  5. bisco

    bisco cookie crumbler

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    is that with the new meter?
     
  6. Mike4kz

    Mike4kz Junior Member

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    I just got a battery in my "more advanced multimeter". Another one gives only two digits after a period, the new one shows three. So, it's more accurate. However, in general, values are about the same (perhaps different "rounding").

    I will check tomorrow, why I don't have a light in the trunk area - not sure if it's just a bulb or the "door switch". All "side doors" switches work fine, the light goes on and off with any door. And light bulb(s), if I remember correctly, take about 1A.

    PS. And thank you for the support. :)
     
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  7. Longinus876

    Longinus876 Junior Member

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  8. Longinus876

    Longinus876 Junior Member

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    I have a similar thing going on now. What happened with yours?
     
  9. Kerrynzl

    Kerrynzl Junior Member

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    Get yourself a small 0.8A CTek battery charger/tender that motorcycles use.[Good Swedish Quality]
    These things are smarter than us!

    The CTek comes with alligator clips, a cig lighter plug, and a plug to hardwire it direct to the battery.

    Then you can leave it on for weeks at a time without worrying about it.


    Here is a little marketing exercise



    upload_2023-5-30_16-1-4.png

    And for Porsche

    upload_2023-5-30_16-4-9.png


    And a CTek [They are all made in the same factory]

    upload_2023-5-30_16-6-55.png
     
    #29 Kerrynzl, May 30, 2023
    Last edited: May 30, 2023
  10. Mendel Leisk

    Mendel Leisk Senior Member

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    Those are all the same charger, and prices in US dollars?
     
  11. Kerrynzl

    Kerrynzl Junior Member

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    Yes, USD $
    Even worse in NZD.
    When I purchased the Ferrari , the dealer left the Factory charger in the trunk [as a "Bait'n'buy" ] and 2 days later wanted NZD $1000 for it.
    I said that if the car needed a recharge after 2 days I'm bringing the whole car back.

    Anyway while the charger was in my possession, I load tested it and also load tested the CTek at our friendly parts store [they were the same]
    And the Ferrari adaptor plugged into the CTek.

    So I purchased the CTek and returned the Ferrari charger [then I mail ordered the Ferrari adaptor plug from the UK]
    I'm into my charger by NZD $180 [USD $108] incl the Ferrari adaptor.

    I had a friend scan the decal on the Ferrari Charger [if I ever want to relabel it]
    But I also use the CTek on my other vehicles and trailer winch battery because of all the other adaptors.


    On a Prius C I would hardwire the CTek adaptor to the jumper terminals
    upload_2023-5-31_10-18-16.png


    I also have a Detran Solar Battery Tender which I also hardwired with a CTek plug [to use the other CTek adaptors]
    This is connected to a 40w solar panel , and I simply leave it on the dash of my Falcon Tow Hack [I only drive this a few times a year and it will slowly discharge the battery]
    upload_2023-5-31_13-56-49.png

    My Solar charger and CTek charger are all interchangeable between each other.
     
    #31 Kerrynzl, May 30, 2023
    Last edited: May 30, 2023
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