It looks like the USB cable that comes with
X9Mi will plug into the female adapter with
solar charger.
http://www.solio.com/v2/shop/shop2_c...es.php?catid=8
The only issue is if it will have enough juice to charge the watch battery.
How many amps does the charger need to work?
BTW there are adapters to plug USB into a 12V car power port too and they work great.