Battery cooling via AC

It is a very briefly displayed message; I used to not catch it in time when I first got the car. I have an Advanced; I wonder if that makes any difference. The message doesn't always display on warm days.

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The traction battery cooler only works during a scheduled charge. Most people do a scheduled charge early in the morning, when the ambient temperature is too low for it to come on anyway. As such, it's a pretty useless function.

 

It is entirely possible that I have missed the display too. Well, I have to wait at least 7 months to see that pup-up. Our daily high has been around 30, and now starting to see low of single digit (in F) in 10 day forecast.

 

The battery's temperature at shut down likely plays a role in whether you see the pop up.

 

On my 2010 HiHy (which is 2nd gen HiHy) I am able to see the fan speeds as well as the battery temperature using Hybrid Assistant android app. The app also allows me to override the fan speed and make it run at higher speeds as well. In my vehicle the battery is below the 2nd row seats and I do not hear the battery cooling fans (there are 3 of them) running till speed 3. Above that they start becoming audible depending on how quiet (or not) it is in the cabin. At speed 6 (highest speed) there is no question of "not hearing" them fans.

Hare Krishna!

 

Yes, may the force be with you.

I was watching battery temps too. I don't feel inclined to second-guess the engineers though: I would think Toyota's pretty cautious when setting fan speeds versus temperatures.

The one exception that worries me: my 2010 will not run the fan once the car's off (maybe the Prime does in some instances?): many times we would arrive home after extended drive on hot day, park in hot (uninsulated) garage. And there it sits, maybe cooking??

I did set up a thermostatically controlled window fan in the garage, with one fan intake, one exhaust, which helped some I think, hope.

Unfortunately the battery is pretty much buried in the car too.

 

The Prime should be able to run the fan while it is plugged in.

 

But otherwise no? I guess not, to conserve juice.

 

That is not totally correct.

If you have no scheduled charging events there is a message for 10 seconds when you turn off the car asking if it can run the traction battery cooler. If you say yes it doesn't always run, but it might. If you plug it in right away it will either start within about 5 minutes or not run at all.

If you have a scheduled charge, but select "Charge Now" then the traction battery cooler won't run because it assumes you want to charge as soon as possible.

If you have a scheduled charge I don't know. I think you'll still see the prompt, then the AC might run if the battery is still warm when it decides to start charging.


I have seen the traction battery cooler message come on on one ~50 degree day, but that was after level-2 charging then driving more aggressively than usual on the way home because I was in a hurry. It only comes on for 10 seconds, but if you miss it after you park, you can put it in Drive and roll forward a foot then turn off the car and you'll get the message again.

 

@Salamander_King Not sure what the temperature is but it is going to be based on the temperature of the battery not ambient temps. I've had the pop-up many times and the cabin or outside temps do not have to be hot, climb over a mountain in EV mode you'll likely see the message.

 

If the car isn't running or charging, then it isn't generating internal heat. So the pack will equalize to ambient temperatures. It would take extremes to 'cook' the pack in those conditions.

 

See pages 127 & 128 of the OM. You may have it turned off. See the part that says

"When the power switch is turned off, a check screen is displayed on the
multi-information display that indicates whether “Traction Battery Cooler” is
implemented. This check screen can be turned on and off in the “Meter Customize”
settings on the multi-information display (→P. 234). However, when
the check screen is set to “Off”, “Traction Battery Cooler” is no longer operates."

 

Thanks. I was reading that page on manual but missed the part about MID pop-up setting. I have not changed any of the pop-up display on the MID from default, so I don't think that is the case, but it is worth checking it. Just one thing. If I'm reading this caution on manual correctly, if you turn off the pop-up display, traction battery cooler function does not operate at all. That seems strange to me. When the pop-up display about the traction battery cooler comes on, if you do nothing then by default "YES" is chosen, thus the traction battery cooler features operate automatically. However, if just do not want to see the pop-up notice to be reminded all the time and turn off the pop-up notice, then instead of keeping it with default of "YES", the traction battery cooler no longer operates? Is this how PRIME really behaves? Or this is some kind of typo.

 

I wondered that as well. I've always let mine run every time it asks. Seems odd that just turning off a screen prompt would kill the process as well. It might be worth a question to Toyota on the customer portal page.

To me, if it's asking, it probably needs to run. I can't think of a good circumstance why an owner would not want the cooler to run.

 

When charging on Level 1, I don't think the car can actually charge the battery and run the cooler at the same instant. So cooler operation means longer charge time. Without the pop up to alert people of the possibility of the cooler running, Priuschat would have posts asking why their Prime isn't fully charged in hot climates.

 

Good explanation. I'll buy that. Only thing is that PRIME does not display any warning about the "traction battery heater". I think the L1 charger with battery heater has the same deficiency as with the cooler, but I have not seen Priuschat posts asking why their Prime isn't fully charged in cold climates.

 

Soooo, is yours set to display the warning? Trying to fix your original issue of no popup.

 

I don't know how it is set in my car. My inclination is, it is set to display the pop-up as factory default setting, but I am away from the car now. I will check it later. Most likely explanation is that I missed the MID display for a few very rare occasions the pop-up might have displayed in my car. Today's high temp is 15F, and the 10 days forecast is showing no warming trend in near future. No worry about overheating the battery for a while.

 

As I understand it, the Prime doesn't display the kWh in the battery, but just the predicted EV range. People already expect shorter ranges in the cold.

Then there isn't much of a risk from not having the cooler on. Heat is bad, so the system has safety measures in place. The battery gets too hot while driving, the car switches to hybrid mode and uses the ICE more until the battery cools down. Too hot while charging, and the car stops charging.

Now if the electrolyte is at 0C/32F or less, and the battery started charging, permanent damage will occur. So there isn't any valid reason to not have the heater off if the car is going to be used in the near future. Then warmer keeps the battery warm so its performance, and the car's, isn't impacted too much by the cold when it leaves the next day. Whereas the negative of leaving the cooler off is that the car might not be fully charged because heat delayed it, or hybrid mode might happen sooner, but the rest of the car's performance isn't hurt.

 

What's the moral of the story then: set your charging timer to start a little earlier, just in case?