It's been in the 100's in the Bay Area last few weeks and I haven't noticed any loss of battery charge or power. Car is parked in the sun all day while I am at work and no issues except HOT in side. I will be getting some window tint next week. Forgot how hot a black interior can get. I am impressed with the AC on the CT it works great. Glad the temps are getting back to normal only in the 90's now.