The XG8 and XG 11, powered by a 2S 1400 mAh LiFe battery, have the particularity to integrate the battery charger into the transmitter case. They need a 220VAC / 9VDC adapter, provided with the radio. This solution works great at home but the downside is when you want to recharge your transmitter on the field/slope, and that you don't have 220V source available.
I found a smart solution to recharge my transmitters on the field. I bought a CCBEC from castle creation, which is programmable using the USB link to purchase separately, and which is the only UBEC to be able to go up to 9V, at the opposite of all other BEC which deliver 5 or 6V, not more.
I prepared some cable to use with the CC-BEC, on one side to connect to the transmitter plug, on the other side to connect to a 3S Lipo battery, or to connect to a 12V power source. I will also prepare soon a cigar lighter plug.
This charging solution is very convenient, in addition to be an excellent backup solution. It's light, can stay in the transmitter bag, so you have it always with you.
Greatly recommended !