Powering Hybrid Battery Fan Externally

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by indel, Jan 12, 2026 at 3:15 PM.

  1. indel

    indel Member

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    I will soon be reconditioning my Prius battery and will take it out of the car to do so. That means, I will need to power the battery fan externally with a 12V power supply. Luckily, I have a spare Prius 12V battery laying around and it's putting out 12.5V consistently.

    1. Is it okay to use this battery to power the fan?

    2. What are the specs on the fan power connector? I would like to put together a harness that goes from the battery to the fan connector. Do they make any specific connectors on the battery end for applications like this?

    I found a video which suggests a frequency meter is needed to select fan speed on later generation Prii. I assume Gen 3 does not have such a function and the fan runs at a constant speed. Correct?
     
    #1 indel, Jan 12, 2026 at 3:15 PM
  2. Tombukt2

    Tombukt2 Senior Member

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    Most people just put a big shot v
    Fan over the rack. I thought. At least that's what I see at my buddies set up wer he does this like production . 18 inch fan above table the racks are on wen charging in singles or complete racks of modules . And it's conditioned space the shop is .
     
    #2 Tombukt2, Jan 12, 2026 at 7:31 PM
  3. PriusCamper

    PriusCamper Senior Member

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    Or you could find a Gen2 Prius cooling fan at the junk yard... It will run straight off a 12v power supply. @ChapmanF pointed out the Gen3 wiring for the cooling fan on here once, but I don't remember what he said?
     
    #3 PriusCamper, Jan 12, 2026 at 7:32 PM
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