So i have an ebike its called OTS 500 its a localy branded and chinese import ebike so i cant find much about it online and i have recently bought a 750$ 30ah 48v lihtium battery that I have already installed and i was expecting the bike to go much faster because it was originally running off 48v 14ah sla's but the bike goes the same speed as before and i really want to get more power to the hub motor which 500w btw. So I figured the controller is probably not strong enough or has littler or weak mosfets so i decided to look at the controller and figure out what it was and it looks fairly beefy but i couldnt find any info about it so I then researched on new more powerful controllers and they are a fair price for about 100-200 bucks but they dont seem to be for ebikes because they dont have plugs for headlight and turn signals and brake and alarm so i messaged the provider because they say the controllers are customizable and i got no reply so now i need help from the forum because im not sure if i need a new controller and where to get it. im so bumed out i bought this expensive battery expecting to go faster please help!