It charged to full in less than an hour (not sure how long, I left it and came back and it was charged). I'll try it in airplane mode this week.I am guessing that the connection between the two is Bluetooth? If so, will it connect with your phone in airplane mode?
That would force the satellite device to handle all of the connections, maybe really test the battery life?
How long did it take to recharge? Do you have a solar charger to try to see how long it would take to recharge or keep charged? Something like you would use in a remote camp?
It charged to full in less than an hour (not sure how long, I left it and came back and it was charged). I'll try it in airplane mode this week.