This is my E36 scooter:-
It's been mentioned on a few other threads... Much progress has been made so I've decided to start this build thread.
I bought this scooter s/h from ebay about 4 or 5 years ago. In it's stock form it consisted of a Unite 1020 36v 800w brushed motor sucking amps from 3x 12ah SLA's. Out of the box is was pretty fun, with exceptional torque and a very reasonable 40km/h top speed. Stopping was done by a rear band/drum brake. Range was about 6kms when ridden hard.
The first upgrade was LiPo power. After quickly destroying 2 sets of SLA's the scooter was ignored for about 18 months. I was regularly looking at lithium packs for e-bikes but the price was always just too much to bear. Eventually I discovered HobbyKing and their Zippy 30c 8ah LiPos. The price was too good to be true so I decided to give them a go! I bought two 5s packs and ran them in series into the stock controller. The scooter was back to life with a vengeance! The reduction in weight and voltage/amperage increase was quite noticeable. Acceleration was much better (esp midrange) and peak speed rose to ~41km/h. The increase in range was amazing!
Prior to getting the LiPo's I added a CA computer. Was staggered to see 120amps max!
The next upgrade was a Kelly controller. I wanted to try upping the voltage. I bought an extra 3s pack to see what 50v would be like. The moment I connected 50v to the stock controller the motor fired up (zero throttle) and that burning smell was released. So I got a higher voltage Kelly, and also upgraded the high current wires to big audio power cables. The results were mixed... While testing with the 10s pack, peak amps rose to 152 but the initial hit from the throttle seemed softer. Midrange acceleration was once again improved, but top speed was unaffected.
So now it was time to add the extra 3s pack... With 50volts max accelleration seemed about the same, but for longer, and the wind noise just keeps getting louder! Top speed went from 25.5mph (41kph) to 32.3mph (52km/h). That's a bit scary on this rig... But after a quick test ride I could smell the smoke getting ready to escape from the motor. I'm sure it wouldn't go for much longer at that voltage. (36v Motor)
Here's a quick youtube:- http://www.youtube.com/watch?v=SCv1-DKJoCU
I did some mechanical upgrades next:- I switched to pneumatic tyres (lighter, less rolling resistance), upgraded to 8mm chain and upgraded to a disc brake
Performance was starting to go backwards... It seems the motor never recovered from that 50v test run and some time later it finally melted.
I'm thinking R/C brushless power next...