Hybrid battery overheating

what are toyotas temp spec parameters?

 

that's normal behavior, and why they have a multi speed fan. but idk the correct temps

 

Just clean the HV battery fan, then you will know if the rise in temperature is related to the HV battery fan being dirty

Best to error on the side of the HV battery being a problem, and plan for that future accordingly.

Wouldn't switching off the car also turn off the HV battery fan which was cooling down the HV battery?

Do you run the AC when using the car?

 

Clean the HV battery fan.

Use the AC whenever the outside temperature is over 27C (80F), this will keep the battery cooler.

If the HV battery SOC is moving up and down rapidly, and hasn't thrown a code (DTC), you can try to recondition it, or plan otherwise.

 

What do you have going on with the car that you need to force charge it to 70%? Is it not staying charged?

 

We need to know the driving conditions when it charges to 3 bars then back to purple. Short trips low speed, sorry trips high speeds, as on or off.

High battery temps can be a sign of a failing battery, but it can also be the result of high cabin air temp, especially in hot environments like deserts.

 

I suggest that you can use A/C to keep the cabin cool. Obviously, 30C air in the cabin can help to cool down a 50C battery. See attached picture. At 20:03:00 I powered the A/C at max (check showed 52C battery temp). In a few minutes temperature dropped 10 degrees with the use of fan, also, at max speed. See picture below. I'm using an app called Prius Assistant for this.

 

Do you use Torque Pro? And will setting the battery fan to high speed for better cooling be possible only when the app is running from OBD2 (similarly to Dr Prius app override battery temperature feature)? Thanks

 

I've used torque, not sure if it was pro or not. Yes, you can only override the fan via an app. Is your OBD2 port currently being used?

 

Toyota set certain fan speeds for certain temps. Is it presumptive to assume lower thresholds for the various fan speeds, or just running it full blast all the time, is better? I'm not trying to be a smart-a$$, just wondering.

 

I just noticed that when I override the temperature with Dr Prius app and the fan started running in full speed the the battery temperature started dropping fast. Still not sure why my reconditioned battery heats up fast in cool outside temperature, my guess the cause is battery modules variation in capacity and internal resistance after reconditioning...

 

Pretty sure I read that the battery will last longer if used or stored at temps around 80F, so that is what I try to do. At max fan speed, and with the AC on, it is hard to keep the HV battery under 90F when driving around. But when parked and using the HV fan on high with or without the AC, it can cool down the HV battery in minutes (assuming ambient is under 80F). The sensors are external, so the internal is likely higher.

Compared to the HV battery, I find it easier and less expensive to clean (or replace) the HV fan.

 

Driving on a coolish evening, around 80 kmh (50 mph), car fully warmed up, no intervention with fan speed, I recall Scangauge II showing me 35C (95F). IIRC, fan speed was 2, or 1, no higher.

I took that to be Toyota engineers’ “status quo” temp, not sure if that’s a leap of faith though.

Maybe involves some compromise, and who knows how optimum that is. I would think they’re conservative though, would err towards battery conservation, if the price is trivial.

I’m debating myself now, lol.