I apologize if it was already asked elsewhere, but I took my P4 out today to retrieve some photos I had in the SD card that I took 2 weeks ago, I always keep the batteries on the side of the styrofoam case the PRs come in, never inside the AC. While I was taking out the AC I touched one of my batteries and found it warm to the touch. It is not bloated, it has charge, but it is strangely warm. The current ambient temperature is around 80 degrees farenheit and the battery is around 90 degrees. The other battery I keep in there was cool. Is this a normal occurence? Or should I worry about this battery? The battery is not the original that came with the drone. I purchased it separately, but it’s a high capacity DJI original one.