the bike is RR DD350e-6c

Only thing i did was remove the back rest, then after wards would like to go around anywhere and it wont start. I have open the lock and switch it on, usually the lights will turn on, but it didnt, tried again and again, i suspect battery but the bike is only 5 days old. it dont have a kickstart so cannot start manually. i have a charger but the owners manual is in chinese and I timbudong.

any guys here have the same model of bike