For the past couple weeks on the way home from work the ICE runs non-stop for 20+ miles. My drive is 25 miles and the weather has been 105+. In the morning everything seems to work fine. In the afternoon even with the AC off, battery almost fully charged the ICE does not shut off at all even at a stop. I even tried putting it in EV mode and it tells me Not Currently Available. My Prius is a 2012 3 with 5500 miles. Is this normal in hot weather or is there something wrong??? Also the mileage sucks, in the morning with the AC on, weather around 90 I get 55-58mpg. In the afternoon I get low 40's even with the AC off.
It's running to power the A/C. This helps cool the big battery (and you also), so keep the A/C on and don't worry about it. Or move out of AZ.
I'm going to guess that the traction battery is getting quite hot while it is parked, and the car is limiting its current for protection. Here are some questions related to that possibility: Is the battery vent (next to rear right seat) fully exposed? A vent blocked by pet hair or cargo or a jacket will contribute to battery overheating. Do you hear the battery fan (behind this vent) running? If the battery is hot, it should be running. (Due to my cooler climate, I've never heard it.) When using AC, are you using the Recirculate mode (default), or fresh (outside) air mode? With closed windows, the fresh air mode should help push more cooling air through the battery vent towards the battery. This won't help when windows are open. Do you have the solar sunroof? It isn't mentioned in your profile. If you do, make sure you have the automatic solar ventilation turned while it is parked, to keep the interior somewhat cooler. Do you have a ScanGauge, or other engine monitor application? If so, there are some special codes to monitor the battery temperature.
I agree with my friends above. It could be the traction battery trying to save itself. I have only had a couple days in the 105F and 107F range but with my solar roof the interior was pretty cool. My mpg was still very high on those days. Could you try some of my car cooling tips to try and bring your interior temps down to a reasonable level?
I do have the solar roof and I do leave it on all the time. I don't have anything blocking the battery vent but I don't remember hearing a fan running either ( I'll check that out) I also found in the owners manual: In the following conditions, the "EV" drive mode may not be turned on. In this case, the message appears I the multi-information display and a beep sounds. -The hybrid system gets hot. (after the vehicle is left in hot weather, after driving on the slopes or high speed driving etc.)
Kinda odd you still have an overheating problem unless you are trying to use EV (not EV Mode) too much as this can really heat up the battery. Here are tips to try and reduce interior temps. How to Reduce MPG loss Because of A/C Use | PriusChat
Also I think, someone correct me if I am wrong, but if the fan is on mid to high speed for any reason even to get fresh air from outside, the engine will run.
What fan are you referring to? I have had both the AC fan and the HV battery fan running at higher speeds and the ICE has stopped like normal.
I was referring to the ac fan, I know on my 2005 if my fan speed was mid range to high speed it would start my engine and run all the time and if I went to slow fan speed it would go back in electric mode when at stop signs and ect.
Well today when I got in to car to go home after setting in the sun all day, temps around 110 it wouldn't go into EV. So like some people said the battery is hot. I cranked the AC and after a few miles EV started working. So it's just the battery needing to be cooler. Got better mileage today with the AC cranked then yesterday with no AC!! Thanks for the replys!
Yes, thanks for the update. Now, is there any way to keep the car cooler? Any possibility of parking in even partial afternoon shade? (though it takes not much shade to shut down the solar ventilation.) Are you using reflective sun shades in your windows to reduce the heat coming in?
No shade were I work, my windows are tinted and I have the cool sun shade for the windshield and I run the solar ventilation. It's just hot here!!
Those make a huge difference. They prevent the seats & dash from being super-heated, something the A/C will have to counter the affects of afterward. Keeping them on the cool side is no big deal. $12.99 for a jumbo (Prius-sized) shade from your local automotive supply store.
Sun shades for all the windows with direct sun, or just the windshield? Heat does seem to be a factor in battery life. If you plan to keep the car longer than the battery warranty, it is worthwhile to try to keep it cooler. But it appears that you have already covered many of the available options.
I always try to aim the front of the Prius toward the sun. It's easiest to shade the windshield and at least a little reduces heat the battery-pack would be exposed to, both inside the vehicle and underneath outside. I keep the shade over the cargo area pulled out too.
