Hi everyone. I recently purchased an Ecoflow delta 2 and have noticed that the fan comes on every 15-30 minutes, for about 15 seconds each time. This happens when the device is plugged in at 100% charge and is not being used. The fan noise happens when the device temperature is about 26 or 27 degrees and the inverter is not in use at all. Is this normal? Has anyone else experienced this? Thanks for your help.