Is Duracell 12V Battery My Problem? - All Warning Lights Appeared+Shutdown

First time after being parked for hours, Sarah tried to start and got red triangle, Brake and VSC lights.

Then 10 days later driving at 60 on highway all warning lights came on again, steering and brake worked minimally, gas engine shut off. Limped off road.

In both cases after it sat, all warning lights went away and back to normal.

0 codes after second time.
after first time, codes non start, abs code, transmission codes, some hybrid battery code, nothing conclusive

Tested battery, seems perfect. Is 3 month old Duracell Ultra Platinum AGM Group 51 Battery. Have driven many problem-free miles til now on it.

Looked at inverter coolant reservoir. Is very good flow with small waves. Is that turbulent enough?

I think key fob battery is almost dead. Was in car but not stuck in dashboard. Could that cause a problem?

Weather only in 80's and driving typically 10-30 miles at a time. Doesn't seem like inverter coolant pump.

My thought is to get a 12V battery from the Toyota dealer under the guess that the Duracell battery is causing trouble. Maybe too high a voltage?

Only other potential clue is my son was in the back and said he heard a vibrating sound in vicinity of rear axle like a diesel truck far away, then got quiet when warning lights all came on. But he is not sure it even came from the car.

Hoping for direction.

 

I want to learn to keep this car well. I will check the fan and clean right away. Thank you for the tip.

The fact that the first incident happened when the car had not been driven all day, but just when Sarah tried to start it in the evening after working all day, and not a hot day, indicated against overheating being involved.

That's why I was reaching for a 12V battery issue...

Had brought Prius home on trailer. Just got it off and drove on fairly flat road gently. Outside air 87F. Lots more to diagnose now. HV battery started at 3 bars. Gas engine started right away and ran, charging battery up to 6 bars after about 1 mile. Then Triangle, (!) and VSC lights came on. Pulled in at a friends and parked while I wrote notes and checked for codes. No codes. Headed home. gas engine would not come on, driving by HV battery. Stopped and turned off 5 min. Restart. Triangle the only light on. gas engine comes on and drives home fine. park and turn off. 12V battery shows 12.8V.

Now I will clean HV battery cooling fan.

Any ideas?

 

Thanks, Bisco. I was wondering about the codes. I will look into getting tech stream.

I pulled the high voltage battery cooling fan. maybe 2 or 3 slits were completely blocked. 5 or 6 30% blocked, but mostly open and not terribly dirty. Definitely needed cleaning and I'm glad to know luscious garage recommends every 60K to clean it.

I plugged it back in its place and turned on the 07 Prius. All warning lights gone, engine started fine. No sound from the cooling fan. Does high voltage battery cooling fan run all the time or only certain times?

 

I looked at 12V battery voltage on the MDF.

with engine off it is at 12.8V and drops to 12.5V with headlights on and right back to 12.8 with them off.

When engine running it says 14.1V.

 

Another test drive after cleaned hybrid battery cooling fan. Ambient outside air temp down to 77F. Drove many miles, no problems.

The hybrid battery cooling fan never came on. Is this because air temp is cool or because it has failed? How can I test?

Seems like the hybrid battery overheating may be the key. Thanks again.

 

I ordered a 64 bit version of mini vci from ebay.

I found
prius how test hybrid battery fan

push power button 2 times without foot on brake. After about 30 seconds I heard clicks and then hybrid battery cooling fan came on. I had already removed the 10mm nuts that hold the fan on the frame, so I loosened the fan and pulled it out of the black duct that goes to battery. I could feel a good flow of air blowing from the fan!

I also found this thread about adding another cooling fan. Adding an additional fan to the Traction Hybrid Battery? | PriusChat

 

Driving great, thanks. I would not have found the fan cleaning without your help here.

I am considering the suggestion to add an auxiliary cooling fan as in Adding an additional fan to the Traction Hybrid Battery? | PriusChat