1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Hybrid Battery Temperature

Discussion in 'Gen 3 Prius Technical Discussion' started by AnneN, Sep 2, 2024 at 6:07 PM.

  1. AnneN

    AnneN Junior Member

    Joined:
    Feb 16, 2022
    33
    7
    0
    Location:
    Ireland
    Vehicle:
    2014 Prius
    Model:
    N/A
    I've recently been monitoring my hybrid battery using Hybrid Assistant and Dr Prius.
    According to Dr Prius the hybrid battery life expectancy is 84% - it is a 2013 Japanese import.
    I have had no warning lights on my dash. Using the OBD scanner no faults are detected but I don't trust the scanner as I don't think it works well on the imported car - I have ordered a Ancel JP700 JOBD OBD2.

    After hearing the hybrid battery cooling fan coming on recently I started using Hybrid Assistant to look at the temps and it does seem hotter than I would have expected - I live in Ireland and the air temp is very cool compared to most other countries. The screenshot (taken just after I turned car off after a 25 min drive on a non congested road) shows the outside temp is 18c (64f), inside car is 23c (73f) with the hybrid battery at 40c (104f) with the fan running on max. Is the battery unusually hot? I have the settings for the fan set at Max 35c (95f) and Min 20c (68f).

    I cleaned the battery fan out last year but just to be certain I took it out again yesterday and it is very clean.

    I also got my 12v battery checked today - I know the voltages are fine 12.8v when off and between 13.5 - 14.4v when on, but with professional equipment they used to check it he said that it was at a higher capacity than it should be - battery is marked as CCA 295A but he said it is showing 445A on the machine - I hope this makes sense? I tried to find out how this is possible but I don't think he knew and wasn't used to a woman trying to dig deeper so I left confused!

    I would appreciated your thoughts/advice on this as I know heat is the killer of hybrid batteries and I'd like to head off any potential problems. I love the car and want to keep it going for many years.

    Thank you.

    Dr Prius.jpeg
     
    #1 AnneN, Sep 2, 2024 at 6:07 PM
    bisco likes this.
  2. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    9,703
    1,697
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    Dang I can't wait to hear some reasonable answers to this because 104° seems awfully mild temperature-wise even for a battery I mean for a human that's very bad granted but for running things like a fan motor or various and sundry other things even the 12 volt battery if the lights are on and the alternators charging it is going to run close to that 100° especially if it's 100° outside or close to it You granted have lower outside temps and on the attempt of 73° in the car but the batteries enclosed and all of that so I would expect it to be able to go up about 30° above your ambient air temperature I would think but I guess this could be bad I don't see how you're going to get it much cooler I never really look at mine I figure if it's around human body temperature to high human body temperature must be okay I'm wondering what the electric car batteries are running at that have all the fancy cooling and plumbing and all of that I imagine they must hit around a hundred 102 something as large as they are the big mass and the density.
     
    #2 Tombukt2, Sep 2, 2024 at 6:56 PM
  3. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    109,389
    49,729
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    i can't answer for the cca reading, but if the car is making 'ready' i can't see it as a problem.
    you might want to open the battery case and see if there is any corrosion or clogging from debris.
    and make sure the fan inlet grille is clear.
     
    #3 bisco, Sep 2, 2024 at 7:38 PM
(You must log in or sign up to post here.)