Hybrid Battery Temperature Getting Warm

I used to have a ScanGauge II hooked up, pretty much constantly, and the highest I recall was around 45C (113F), in stop-and-go conditions, but it wasn't that hot/extreme. I'd suspect 50C (122F) would occur easily, stop-and-go in very hot climate.

I would start by checking the condition of the hybrid battery fan: they can get clogged with lint and dust. There's a fan cleaning video, by @NutzAboutBolts, linked in this thread:

Nutz About Bolts Prius Maintenance Videos | PriusChat

(video #21)

I wouldn't bother removing the rear seat bottom though, it's just more work. There's one bolt (12mm socket size) you need to remove. If you push apart the seat bottom and back portions, just below the fan inlet grill (on seat back), the bolt is in behind there, reachable with an extension on a ratchet wrench. Just be careful not to drop it.

 

When I had 45C, I was also monitoring fan speed, and it got up to "4", and I believe there are 6 speeds? So the car's computer was not overly alarmed.

 

I was using a scangauge II with extra "gauges" code added (called XGauge), for hybrid battery temp and fan speed.

I had it connected constantly, but unfortunately it seemed to be the source of communication errors, perhaps due to constant weight on OBD port, so I discontinued use.

 

The app is showing atleast 3 bad cell modules. Block 5, 7 and 9

The second shows block 13

7 is for sure bad and must be replaced.

Posted via the PriusChat mobile app.

 

1) I don't think you can make that conclusion based on only 2 screen shots.

2) The voltage differences between the highest and lowest blocks are well within an acceptable range in both instances. In the first instance, the voltage difference is .10V. In the 2nd, it is .14V. For the Battery ECU to throw a code, that difference has to be above .3V on a consistent basis, I believe.

Based on the admittedly limited information provided, his battery seems to be in good condition and well balanced.

 

The app is spot on to help you find bad modules, I use the app and it showed for me block #12 was bad. I opened the hybrid up and and tested all modules and in fact #12 block is bad. So based on that I can tell him the cell module is bad.

Posted via the PriusChat mobile app.