Are you using rechargeable battery?
When you car is really hot under a Summer sun would it be safe?
I have bought a 17670 rechargeable battery and I am still hesitating whether to put it in my car or not.
BTW, when I use Ultrafire LC17670 3.7V/1800mAh rechargeable battert in the P3D I can only use the turbo and strobe mode. The general mode did not work at all but flicker.