HV Battery Not Cooling - Need Help
 

Hey guys so I noticed for the first time on my way home yesterday that my battery was not cooling at all. I got in the car and the battery temp on my scangauge said 102 and at the end of my 25 minute commute it said 104 and a wrench light came on.

I thought it was the actuator door but I felt the AC lines underneath the car after driving it a bit last night and they were not cold at all. I know for sure the battery AC was working properly before as the temp would get into the 70's easily if it wasn't too hot out. I also checked the AC lines underneath the car by the battery a few weeks ago just for the heck of it and they were ice cold.

Is the AC for the battery independent from the cabin AC? Is is possible a leak developed that quickly?

Can I buy a "recharge kit" at autozone and use it in that system?

I am very mechanically inclined and I'd love to see if I can fix it w/o taking it to a dealership. Thanks for the help!

Re: HV Battery Not Cooling - Need Help
 

The battery aux A/C and the cabin A/C use the same compressor, so if both are not cooling, chances are you have a leak. No kit will fix a leak. If the cabin A/C is cooling, you may have battery fan problems.

Gary

Re: HV Battery Not Cooling - Need Help
 

Battery fans are working fine as I can hear them very easily. Also the cabin A/C works well and I just checked the charge in the car a second ago and it is charged perfectly. Still the lines running to the battery are not working consistently.

I say that because after not driving the car yesterday I got home from work and moved it into the garage to finish replacing my lower control arms (ball joints were shot) and I felt the lines again and they were ice cold. So I started the car again after I realized that and they didn't cool off again. So it appears to be intermittent.

Could a fan problem prevent the A/C lines from turning on (cooling off)? Could a AC Door Actuator have a problem as well?

Thanks for the reply btw. I appreciate it.

Re: HV Battery Not Cooling - Need Help
 

When it doesn't seem to be working (TAV going > 86F) try turning on your cabin AC (turn it to the red zone) and see if TAV starts to drop after a few minutes. This is what is happening to me. I monitor AC on the scangauge and can see the AC cycling on and off every 5s or less when the system is trying to cool the battery. However this is not effective and TAV climbs. If I force the AC to stay on with the cabin switch it will eventually cool the battery back down to 78F in 10-15 min (then I turn the AC off). Still don't know why this works or what is broken to cause the problem in the first place but others seem to have the same problem. Any ideas would be appreciated. Craig

Re: HV Battery Not Cooling - Need Help
 

In my original post I described the time where I got into the car and drove it home for 30 minutes. During that time I put the AC on it's MAX setting to the ICE would never turn off but that made zero difference and the TAV raised to 104 before I got home.

I can force the AC to run and it cools the cabin, but again the lines running to the rear of the car are not cooling and therefor the battery is not being cooled.

As I understand there is a AC solenoid that regulates flow towards the rear of the car, correct? Could a faulty solenoid be preventing the lines to work properly? Does anyone know where the solenoid is located?
- That seems to be the only thing I can think of at the moment...

Re: HV Battery Not Cooling - Need Help
 

I have to tell you one of the first FEH owners on this site did develop a leak in his cooling lines to the HV battery. He did add a "stop leak" solution and claimed he has not had an issue since which is now several years. A cheap possible solution.

Re: HV Battery Not Cooling - Need Help
 

That sounds to me like the most likely cause. As you said, the cabin A/C works fine, just no cooling (warm rear A/C lines) to the HV battery.

Re: HV Battery Not Cooling - Need Help
 

I know that the system isn't leaking because the front and rear AC systems are connected and I checked the pressure today and it's perfect.

Re: HV Battery Not Cooling - Need Help
 

Yeah it's weird.. I might just take it to a trusted family mechanic of mine and show him what it's doing and see if he's brave enough to try and tackle it even though I'm fairly certain he doesn't hardly work on hybrids if at all. I really hate paying people to work on my car though. :(

Thanks for the help though.

Re: HV Battery Not Cooling - Need Help
 

If there are contaminants in the A/C lines, I suspect they wouldn't cool very effectively.

Also probably not related but maybe worth checking is to see if your FEH still has the origninal MECS pump. Lots of posts on this site about this topic.