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DIY harness for DIY charger/discharger

Discussion in 'Gen 3 Prius Accessories and Modifications' started by edu4prius, Jan 17, 2021.

  1. edu4prius

    edu4prius New Member

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    I already have everything set up, I'm just waiting for the fuses to make it safer, but adding they in the middle of each wire is not a big deal at all. I think all the info you need to make your own is already gathered in this post and Abarnabe's post.
    If you have further doubts, feel free to ask here and me or others will try to help you. Good luck!
     
  2. PriusII&C

    PriusII&C Active Member

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    Thank you, @edu4prius.

    I have 2 Prii (a 2012-Two and a 2012-C) and both HV batteries work fine now (actually the -Two is still under 10-year 150k mile warranty). I just try to get myself educated in advance for this project in the future.
     
  3. PriusII&C

    PriusII&C Active Member

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    @edu4prius How is DIY status? I wonder if you could help me with the following:

    1) Why do you leave the fuse inside the battery pack (Prolong does the same)? Is this to prevent a shorting inside the battery pack cover? I thought it would be easier to replace a blown fuse if it is left outside.

    2) What is the amperage for the blower fan? How to control the speed?

    3) You mentioned that the blue wire is used to turn on the fan when car is on. If one plans to recondition/rebalance the battery pack only with car off, this wire is not needed, right?

    4) No air flow (fan) is needed during discharging, correct?

    5) The 257V 0.35 A LED driver is also good for a Prius C HV battery, right? There are only 20 modules for Prius C vs. 28 for Prius Gen 2-3.
     
  4. ChapmanF

    ChapmanF Senior Member

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    I'm not edu4prius, but I can think of a couple things:

    • You do want it to protect as much of your harness as possible.
    • How many times are you planning to have to replace it? (And if your answer is greater than "zero", what are you doing wrong?)
     
  5. PriusII&C

    PriusII&C Active Member

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    @ChapmanF Thanks. I wonder how the battery ECU manages SOC of the newly reconditioned/rebalanced battery pack since the old 40% - 80% SOC operation range becomes invalid.
     
  6. edu4prius

    edu4prius New Member

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    As Chapman said, the closer to the battery the safest it will be.

    I don’t know the amperage it needs. I can take a look to the 12V power supply I use to let you know that anything equal or greater to that will do the job. I also don’t know how to control fan speed, I guess rising or lowering the input voltage would do, but haven’t tried.

    I actually said that it can also be used to force ventilation when the car is on, kind of a bypass to the ECU. In order to run the fan with the car off that connection is needed in addition to the 12V power supply. In my case I used a switch to leave it in the car permanently, but if you are not planning to make a permanent fan harness, it’s good with just placing a little wire between those pins to turn the fan on and removing the wire to turn it off.

    While discharging there will also be some heat, but probably not too harmful. Anyway, I would let the fan turned on just in case.

    I don’t think so. NiMH cells charging voltage is something between 1.4V and 1.6V. A 20 module battery has 120 cells, hence the charging voltage would be around 168V and 192V, so 257V is pretty far away from ideal. Maybe it’s not that dangerous, but I would not try unless someone more experienced confirms this.

    Hope this helps. Good luck!
     
  7. PriusII&C

    PriusII&C Active Member

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  8. PriusII&C

    PriusII&C Active Member

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    Yes, I noticed the difference, and have the same concern.

    According to this article, it seems that NiMH batteries can be safely topped up in a standby mode at a current of 0.05C. If that is true, then high voltage chargers don't damage a NiMH battery as long as the charging current is regulated correctly. For the LED driver you use, it is around there (0.054C to be exactly). Of course, it will be nice if someone can confirms or invalidate this.
    NiMH battery technology, how to charge Nickel Metal Hydride Batteries tutorial for design engineers, as well as NiMH chargers. .
     
    tungm and edu4prius like this.