Big battery testing

Discussion in 'Prime Care, Maintenance and Troubleshooting' started by IABoy987, Jan 5, 2026 at 10:58 PM.

  1. IABoy987

    IABoy987 Member

    Joined:
    Nov 25, 2011
    205
    80
    0
    Location:
    Iowa
    Vehicle:
    2018 Prius Prime
    Model:
    Plug-in Base
    Not sure if this is right category for topic
    Within the last month or so I have noticed the battery icon shows the battery where the blue is below the charge line, almost zero. As we drive the blue slowly climbs up to where the charge line is. Also we are no longer getting the driving range of a full battery, even on a good day of no heater or any accessories that rely on big battery. Used to be 22+ miles, now lucky if get 14 miles before ICE kicks in.
    Wondering if Toyota can do a big battery load test, or is it time to think about a new big battery?
     
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    114,206
    52,062
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    how many miles? can you post a pic of the charge icon? are you aware of winter effects on range?
    tech stream can certainly do a load/capacity test on the battery, but without any dash lights, they are just gonna call it normal degradation.
    a new battery might cost more than a new car, better to live with it imo.
     
  3. David Lopez

    David Lopez New Member

    Joined:
    Saturday
    4
    1
    0
    Location:
    85143
    Vehicle:
    2026 Prius Plug-in
    Model:
    Plug-in Base
    If it is an old battery, 3rd gen. You could have a person who knows how to get into the hybrid battery and test each cell. I had mine checked and found a few cells that were bad and had them replaced/balanced. Fixed the range of the battery.
     
  4. IABoy987

    IABoy987 Member

    Joined:
    Nov 25, 2011
    205
    80
    0
    Location:
    Iowa
    Vehicle:
    2018 Prius Prime
    Model:
    Plug-in Base
    I checked with my Toyota dealer and they said not to worry that if something is wrong with battery or charging you will see error light(s) and/or message. Does not give me alot of confidence.
     
  5. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    114,206
    52,062
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    that's how mechs are trained these days. if there's no code, there's no problem