www.youtube.com/watch?v=95DGZ94Nq9s

When I was at the Maker faire 2009, I saw this guy pass me with a electric scooter. I remember seen that scooter on the internet, his personnal website http://blog.evplasmaman.com/.

I yelled  ” hey man” and he stop and we start talking. His name is Jos

He use a 3000W ( 4HP ) AXI 5345/18 GOLD LINE brushless motor.

He also use Lithium Iron phosphate (LiFePO₄ ) battery

The setup use 48 A123 cells.  4 cells in parallel and then 12 sets of those in series to make ~42Volts.

Is top speed is 20Mph. He also has a 3:1 planetary gear box. It turn out to be 4:1 with the ratio of the chain.

The gear box is from Matex gears.

You can find more picture here http://photo.gangus.com/v/Jos/scooter/ and on his personnal blog http://blog.evplasmaman.com/.

http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=9177

Spec.
Minimum Capacity: 5000mAh
Configuration: 4S1P / 14.8v / 4Cell
Constant Discharge: 20C 20 x 5 = 100A constant discharge
Peak Discharge (10sec): 30C 30 x 5 = 150A burst
Pack Weight: 536g
Pack Size: 148 x 49 x 33mm
Charge Plug: JST-XH

I got 2 of those battery, when charged a battery like this equals to 16V. In series I will get 32V. I plan to have 4 battery like this. No not 64V it will be 10Amps at 32V. I only bought 2 for the moment so I could test it out first.

Choosing the battery voltage was hard. I could of bought 18.5V, so once charge that would o around 20V, so this mean I would have 40V in serie and my motor can got up to 39.5V. This was sort of perfect. I could of seen the real maximum speed I can get with my scooter ( one of the major goal of this project ).

I choose 14,8V for a couple of reasons. First, all the cheap charger I found, would only charge 14,8V packs. Second, I could use those 14,8V pack in future project like a segway and 3kg sumo robots ( The motors I am looking for run on 14V ). Third, I would of needed to buy a separate cell balancer because my current charger does not have that. And also, if I decide to make a other scooter and get lower wattage motor, they all seem to run at around 30V and lower.

One day, I might and would love to try at 40V, the max rating of the motor. I hope I could get a sponsor for the battery, that would help.

I also got some cheap charger, the charger I got has built in balancer. Balancing the cell mean that each individual cell are check to be sure that they all have the proper voltage before been used. This prevent damaging the pack if one cell could be discharge to much, below the recommended voltage.

http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=2055

I also bought some wire extension for the balacing cable. I will be able to only get the cable out of the scooter to make easy charging. I bought 2 charger so I could charge both battery at the same time! I might have a charger on board of the scooter. The only drawback is that the charger works only on 12V, so I need a power adapter to get 12V. At home, that is not a problem since I use a old computer power supply. If I bring my scooter at school, I might need a adapter for the 12V on board.

Since the beginning, I am think about a version 2 of this scooter. The main modification would be using inflatable rubber wheels. Going 36km/h on 5inch plastic wheels is pretty cool but makes a lot of noise and breaks the wheels. In Québec, the roads are not pretty, so I need other kinds of wheels. I order from AllElectronics.com and I did receive my order. The wheels are cheap but the gearbox are pretty nice.

The gears you see are planetary gear box on your left  and a roller bearing on your right hat only spin in one direction. Like the pedals on your bike. They both match perfectly and I already have ideas how to use them. It is going to be really easy! Can’t wait to start that project.

I also added a Donation button, I have seen website that had those and said, why not? So if you love what I am doing and would love to help me buy more battery, please make a donation!