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Battery not charging on decent

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by priusjunky, Jul 21, 2005.

  1. priusjunky

    priusjunky Junior Member

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    Fellow Drivers,
    I am curently on a cross country trip. Many miles behind and many to go.. I have seen all states of battery charge on the trip. Today, on a long ascent some where in Utah, the battery state was vey low. One bar on the maroon color. When we crested the hill, the battery did not begin to charge as usual. It was a several mile decent. When coming off the accelerator, normally, the green arrows show the battery charging. This time the there was no indication that the battery was being charged. The display showed the the ice was still in use.
    As we started the next climb, the ice was doing all the work. I pulled over and let it rest for a couple of minutes. After restarting, with no indicator lights showing a problem, we climbed the grade. Slow going with no battery assist. When we crested again. Same problem. This time I touched the brakes. Then the display started to show the battery being charged. It was a short decent. The next climb was short. The next decent, with the display still showing one bar, I changed to brake mode. The display showed the battery charging.
    My question, has anyone ever had this problem witht the battery not charging when it is in such a low state and on a big decent, with no pressure on the accelerator?

    Lou
     
    #1 priusjunky, Jul 21, 2005
  2. Frank Hudon

    Frank Hudon Senior Member

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    actually no I've never seen that. I've always had a charge to the battery when decending hills no matter how small. On long hills without braking I've had the battery go all the way to the green and full. On all 3 Prius that we've had. What is the BSOC on the next day is it up or still 1-2 and pink? If not up I'd drop into a Toyota dealer and tell them the HV battery isn't charging. They'll hook the THHT and that will tell them if it's charging or not and what the actual state of charge the battery is in. IF it's markedly different from the MFD have them start a report on the car to log this annomoly. It might be normal (I don't think so) and you'll have peace of mind.
     
    #2 Frank Hudon, Jul 21, 2005
  3. efusco

    efusco Moderator Emeritus
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    It depends on your speed and the grade of the descent. If it is not a steep grade and you're going fairly fast and using cruise control the car can automatically go into a 'no arrows' type of glide to maintain speed.

    If you're not in CC and your foot is totally off the gas and you're in Drive or B you should get green arrows.
     
    #3 efusco, Jul 21, 2005
  4. priusjunky

    priusjunky Junior Member

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    Thanks, I'll monitor the situation tomorrow. If it happens again, I'll stop at the closest Toyota dealer. The battery does hold a charge over night, so I don't think that is the problem. It was just wierd that the battery did not charge on the big decent. CC was off.

    Lou
     
    #4 priusjunky, Jul 22, 2005
  5. myride

    myride Junior Member

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    I think we all know that the battery soc is NOT linear and that the full blue bar lasts a lot longer than the last blue one. So maybe the uphill was enough to get the battery to a REALLY low single bar and it was trying to charge it back up but then the next hill came and back down it goes. Seams to me thats what would happen if the veh is used for really long and hilly (more up hill than down) areas. Or the battery does have a problem but ill put my money on the hills as being the problem. 8)
     
    #5 myride, Jul 22, 2005
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