DJI Phantom 4 Series Battery Cooler.

thingiverse

Here is a cooler for your Phantom 4 series batteries. After a summer flight, put your battery immediately into this case to cool it down quickly. Add two 40mm fans on both sides: - The bottom fan spins counterclockwise - The top fan spins clockwise for air extraction Most of these fans are available in either 5 volts or 12 volts. I used one in my car during long drone operations where batteries face a tough time. You can also charge the battery at the same time with the hole at the bottom. Always cool your batteries for 30 minutes to an hour before charging again.