Configuring audiovox GMRS1072CH walkie talkie

Question

i bought this GMRS1072CH - 10 Mile 22 x 38 Channel GMRS 2-Way Radio Twin Pack walkie talkie from USA and now iam in india..
first of all it cant get it to charge here from the same docking station as it only has input of 120 v and here in india its 240 v .. though iam using a different battery charger for cells to recharge..

and i really can figure out how the Vox works i did try matching the frequency manually..i could here and send voice but Is there any way it scans and pairs to frequency automatically? and battery dies quickly.
and how to maximise the output of my 2-way radio.
thanx hoping for quick reply with some step by step guidance. thanx