I recently replaced 16 out of 28 modules by newer ones (that I reconditioned) and I reconditioned the rest of my old modules. I see in my Dr Prius app battery monitor my HV battery is heating up in cool weather fast to over 110°F (though I've never checked it before reconditioning, who knows what temperature and how fast the battery heated up then...). The battery's blocks IR varies from 21 to 24, also the battery's modules discharge capacity is ranging from 6350 to 5130 mAh. My guess such variation of IR and capacity causes the battery quick heating. Am I correct, can anything be done to fix it?
The IR measure is not the best way to address this as even a rebuilt pack that tests with perfect IR numbers can have a cell that is running hot, which is likely the situation you're dealing with. A thermal camera is the quickest way to diagnose this... If you you know anyone who does home inspections, that person likely has an IR camera you can borrow.
What I want to know and haven't done any research into it all is what is the average temperature one of these battery packs should be running at on a 75° day driving down the highway or doing normal things. I've never seen one overheat that I know of I know that even in the summer with the air conditioning on and me driving 75 mph down the highway for hours at a time when I pull over at Sheetz or loves or wherever if I get out of my car open the trunk lift up the little tray which is not screwed down in my car on purpose I can feel all along the bottom of the battery and it is like lukewarm to the touch it's a tad warmer than I am and I'm 97 98° right. When I run my hand along the bottom edge of the tray everything is pretty even I would say maybe 105° somewhere in there and I haven't even heard the fan running which generally you can't hear I guess. Then when I go into the loves use the bathroom do what I do come out touch it again I can feel the temperature is going down I'm starting the car taking off again. So I don't know what hot would really be would I touch the case and it would be like burning my hand 140° or what?
I have a flookie thermal imaging device I hadn't thought about using that to shoot the battery maybe that'll be one of these things I do one of these weekends