Would the "iMaxRC iMax B3 Pro Compact 2S 3S Lipo Balance Battery Charger" work for a 3 cell Li-Ion battery? It is the stock battery from Redcat's Volcano 18 V2 so 7.4v.

cimg1.ibsrv.net/gimg/www . rctech.net-vbulletin/2000x1124/80-20180123_130420_1__1b9f17491837f685dfb616679b2a32d 439a32736 . jpg
(Input and output for stock adapter)