Hymotion died - plan to remove it this weekend

Discussion in 'Gen 2 Prius Accessories & Modifications' started by bzbee, May 2, 2024.

  1. bzbee

    bzbee Junior Member

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    We bought our 2007 Prius back in the summer of 2016 with over 100K miles on it. It was used by an Electric Coop in Illinois and had the Hymotion kit installed in it. We've had a good run with it (over 60K miles) in the last 8 years. The Hymotion kit stopped charging sometime in 2022 and I believe it has reached end of life.

    Last month the car threw up the red triangle with the PA080 code. So I plan to remove the hydrid battery to trouble shoot - hoping its just a clogged fan or corroded bus bars. At worst one (or two) bad module or cell. Techstream shows good voltage for 13 blocks (about 15V) and only one block that is at 13.7V.

    Anyway, after putting it off for 2 years, I finally decided to use this opportunity and remove the Hymotion kit from the car myself and reclaim the trunk space and maybe get some better fuel economy (I am averaging 38-40 mpg now). I've gone thru the old posts but no one seems to have actually removed it from their car. Found one guy on Reddit who did it but didn't post any details. When I asked him about it, he just said "Long and tedious process. I did it by eye and just looking and where cables lead and unplugged every possible thing."

    I have the Hymotion installation manual, and I plan to just follow it in the reverse order. If anyone has done it before, then please post any advice/tips. Especially, on how to get the nearly 200lb battery out of the trunk safely.

    Wish me luck.

    Cheers.
     
  2. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    I'd probably rent an engine hoist?
     
  3. dolj

    dolj Senior Member

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    Likely only one of the two modules in that block has a failed cell. Your only option is to replace it with another module with the same capacity as the others then it would be a good idea to use a grid charger to do three cycles of charging and discharging with a final charge at the end. If all goes well that should take a week of downtime.
     
  4. bzbee

    bzbee Junior Member

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    Had a burst of enthusiasm in the evening and got to work. Two hours later both batteries (Hybrid & Hymotion) are out of the car and on my garage floor :D

    That was my backup plan if we failed to get it out ourselves. Four of us (me and three teens) got it out in about 15 minutes. We planned our strategy before hand and rehearsed it. First lift the battery straight and turn it slightly so that the pot (that goes into the spare wheel well) is out of the well and rest it on the edge. Then reposition ourselves and lift again to turn it completely so that the battery is length-wise in the car. Once that is done, it was easy to get it out of the rear hatch.

    Yes, I will open up the battery tomorrow and test the voltages. Will probably have to buy one or two new or reconditioned cells.

    I also am planning to order the CQ3 Quad Charger that is recommended in most of the YouTube videos about rebalancing the hybrid battery cells with the 3 discharge-charge cycles.
     
  5. jeff652

    jeff652 Senior Member

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    I am not sure which videos have recommended this charger, but according the link below, the description says that it is NOT meant for hybrid car batteries, but more for RC cars.

    EV-Peak CQ3 Multi Charger 4x 100W NiMH / LiPO with Built-in Balance

    If you have the links for those videos, I would be interested in watching them to see how they are using them.

    Here is the link to another grid charger and discharger that a bunch of people use here on PC:
    Prolong Deluxe Reconditioning Package – Hybrid Automotive
     
  6. ZZprius

    ZZprius New Member

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    I have a 2009 Prius that had the Hymotion A123 and it gave me a 12 blink message (If I remember correctly - whichever one that means that one of the cells needed replacement).

    I postponed the fix for sometime and decided to remove it eventually. I didn't have a manual per say but I took it apart piece by piece.

    First the cover, then the individual cells (After unplugging each wire from the back side of the battery cells), removed all the cells one by one, then I was left with the "bottom" part, it took four bolts that I had to hold still from under the car to get them to unbolt.

    Then I removed the bottom piece but realized that It was attached to the bumper outlet without an easy disconnect. That's when I opened the screws from the very bottom (which automatically voids the warranty but we both know there's no such thing at this point) and disconnected the wires going to the bumper plug.

    It just took a bunch of elbow grease to unbolt everything with either a 10 mil, 12 mil, or an 8 mil socket/wrench.

    I kept the bumper plug and simply folded the wires behind the Driver side tail light, then reinstalled the trunk spare tire/storage. It felt good to be honest. I could tell the Prius "liked" it and looked better overall (Height and feel).

    Now I don't know what to do with all of it. Thinking of taking everything to a recycle plant or salvage... or?
     

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    toymo and bzbee like this.
  7. bzbee

    bzbee Junior Member

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    Lot of discussion on PC and other forums about using Hobby Chargers for Prius Hybrid battery reconditioning. The small chargers do it cell by cell instead of the whole battery at once like the Prolong Charger. Each module in the Prius Hybrid pack is made of 6 NiMH cells and can be reconditioned very well using a hobby charger. Here are some videos:





     
  8. bzbee

    bzbee Junior Member

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    If you just want to get rid of it, post it on Facebook or CL and someone will come pick up. Lithium batteries are $$$.
     
  9. jeff652

    jeff652 Senior Member

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    Ah, gotcha. Yeah, that is a very inexpensive way to do it, for sure. The small hobby chargers look to me like something that could be used to diagnose an issue, especially with a bad module, but if you plan to keep the battery maintained well for the next few years or so, then it might be wise to invest in a charger/discharger that does the whole battery at one time. But there is a time and place for them, like if I was buying this to just sell the car as soon as it's fixed I might get the hobby charger 'cause it's cheap, but then again, I might be able to find a good used Prolong charger and sell it with the car so the buyer has a way to keep the car alive for a while at least.

    So the hobby chargers are not meant to charge the entire pack at once, but you can still make it work if on a budget. BTW, thanks for sending those videos to me! It was good to watch the way other folks work this issue out.
     
    #9 jeff652, Jul 23, 2024
    Last edited by a moderator: Jul 24, 2024
  10. toymo

    toymo Junior Member

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    @ZZprius = Interesting configuration on the Hymotion 2x7 stuff. I'd rebuild them if I could find spares that look like that. Otherwise it's going up on eBay for parts. Good looking out!

    P.S. Thankfully I don't have that style. I will post my funny setup sometime soon when I get the time to share here with y'all.