I live in Dallas, TX and we have had 32 100 degree days in a row. As a result of this the hybrid battery fan has been coming on more and more frequently. For some reason, this is causing my car to not use the hybrid battery when accelerating. When I go to accelerate the car takes 2-3 seconds before it will begin driving since it is not kicking on the electrical hybrid system as usual when I begin to accelerate. Eventually the car begins driving normally after about 10 minutes of driving or so. Please help!
I think you have mixed up cause and effect. Your HV Battery is too hot, so computers start the fan to cool it down. The computers protect the HV battery from further overheating by reducing use of it. Meanwhile you, the owner, turn on the A/C so you cool down. This also cools the HV Battery, so the computers allow it to be used more once cool. The fan is an effect of the computers response to high battery temps, the reduced power is also an effect of the computers response to high battery temps, once those temps come down, both effects are minimized.
The hot days are causing the hybrid battery to get hot, so the HSD system is using the battery less to prevent overheating and the fan is coming on to actively try to cool down the battery. So the hybrid battery remains hot, it is primarily using the ICE to drive the wheels. Since the hybrid battery air intake is from the cabin, the cabin temperature directly affects the hybrid battery temperature. I suggest trying these things if you aren't already: 1) Reducing the cabin temperature while parked by parking in a garage, shady spot, using a sunshade, and/or leaving the window open a crack 2) Reducing the cabin temperature when getting in the car by opening all the windows to immediately flush the hotter cabin air with the relatively cooler outside air, then turning on the A/C to cool the cabin. It's been >100 degrees in the past couple of days for me as well, but I use a sunshade and park in the shade when possible and my hybrid battery fan hasn't been coming on. I've only had it come on when I stress the car on steep hilly inclines.
What is your SOC (state of charge) when this happens? I notice that heavy AC use in traffic will deplete the hybrid battery quite a bit and this will result in sluggish performance.
Also, besides being over 100° F, it is also more humid than any reasonable person should ever tolerate, which requires even more energy from the AC system than just the temp would indicate.