I've marked a few possible places for additional battery mount.
What do you think is the most reliable place to mount battery in terms of ergonomics of the bike? Also, how to ensure the parts are having waterproof connection?
Model is OIO City Bike
Wheels diameter: 26 inches Motor: 350 Watt, brushless, maintenance-free Speed: 35 km / h Weight: 21 kg Load: 120 kg LCD Display (KBY-DISP KD21C): Indication of battery charge status, support level, speed Number of gears: 21 Brakes: Disc Frame: Aluminum Battery: 36V 10.4Ah Li-ION