I picked up this little ride today for $80 on craigslist. The SLA batteries were dead and the motor controller was burnt out. I didn't really care since it was so cheap and I was just going to upgrade it anyway. The motor controller was inside the motor case which was a royal pain to get at and then it was buried in epoxy. I took the motor apart and discovered it was a decent outrunner in there. So I pulled the stator out, removed the controller board and all that epoxy and then rewired the motor fields and halls for an external controller. It's over kill I know, but the smallest motor wire I had was 10 awg. Well it definitely wont starve for current! I have a couple of 1500 watt Chinese controllers so, one of them went on this outrunner. It's wired delta. I was tempted to bring all the field ends out of the motor so I could switch from wye to delta, but truthfully it has plenty of torque from a stop so there's no point. There's a sticker on the motor that says it is a 500 watt motor and I would have to agree that the controller might have been good for 500 watts, but the motor was wound with 14 awg wire so clearly it had more in it that 500 watts. Originally it ran off of 24 volts, but since the 1500 watt controller is for 48 volts, well...you know I had to run this thing off of 48 volts. I have a couple of old 6S LIPO packs so that's what's in the scooter now. I'll likely buy a couple of new LIPO packs since one of the two packs I have is bulged pretty badly.
The motor since it is smallish wattage wise got pretty warm under load and needed a fan on it. I cut the top off the heat sink can and then glued a PC fan to the motor bell to pull air into the motor. There's a small gap around the motor bell and the heat sink that allows air to blow back out of the motor. It works quite well. Running, the air blowing around the edge of the motor bell is pretty significant. Tonight, I took it for a ride and rode full out for several minutes. It goes about 30mph now which is impressive considering how these things did maybe 20 MPH originally. It' doesn't accelerate as well as my blue scooter, but hop on and it takes off on it's own...unlike the moped.
I know this is kind of ugly looking with the deck lifted up on strips of wood, but this is just proof of concept right now. I'll build a better battery box later. This one is completely open from the front and back which allows whatever dirt, grass and water into the battery bay. This is a cludge for the moment.
I have several 12S BMS's. I'll put one in here after a while too. The scooter has no lights on it or horn. It has a rocker switch for turning off the power. I'll have to rewire things after a while so the switch enables the controller, not turn on the power. The thumb throttle is pretty bad. It works, but it has dead spots and sometimes skips. I'll have to replace it too.