DrivetrainMotor and ControllerRear View
OwnerBarron Greig
LocationMesa, Arizona US map
Web/EmailWebPage email image
Vehicle2006 Sun EZ3-AX
Aluminum chassis
Disk brakes on all wheels

MotorMAC-BMC Brushless DC
Custom 750W obtained from EVDeals
DrivetrainCurry planetary gearbox (4.8:1 reduction) with 19 tooth sprocket. #25 chain to 45 tooth sprocket to give total reduction from motor to wheel of 11.4:1.
ControllerPowerPack
Custom controller obtained from EVDeals. 24V-48V with maximum current of 35A
Batteries3 Power Sonic PS-12120F2, 12.00 Volt, Lead-Acid, AGM
System Voltage36 Volts
Charger DieHard 200.71219
This is a 2 A, 12V charger purchased from Sears. It has float mode monitoring. It gets very hot, so efficiency is poor.

Originally I used a Century 87062C. The gauge indicating charging current became inaccurate after 100 miles of charging. After 140 miles it suddenly put out only 10.5 volts so I threw it in the trash.
Top Speed20 MPH (32 KPH)
Was originally geared for 25mph but now geared down to improve range, acceleration and ultimately towing capability.
Range10 Miles (16 Kilometers)
Watt Hours/Mile72 Wh/Mile
EV Miles
Current:177 Miles (284 Kilometers)
 
    As of 6/16/2007
Seating Capacity1 adult
Curb Weight85 Pounds (38 Kilograms)
Bike: 45
Batteries: 27
Motor mount: 3
Battery box: 3
Motor & controller: 7
Future plans for trike in descending order of priority:

1. Battery trailer for extended range. Currently the tricycle has a range of about 10 miles. A trailer will be built to hold 3 12AH batteries, effectively doubling capacity. A 20 mile range will allow commuting to work. Work is 15 miles away, but the intention is to deplete batteries no more than 75% to avoid premature battery failure. Doubling battery capacity should actually more than double range because effective battery capacity is dependent on rate of depletion. Currently, an average of around 20A is being drawn from each battery which results in an effective capacity of less than 7AH from a 12AH battery. With double the capacity, only 10A will be drawn from each battery which should raise effective capacity to around 9AH.

2. Fit solar panel to battery trailer. While I'm at work, the bike will charge for the ride home.

3. Add bracing to axle unit to further reduce flexing. Flexing may lead to fatigue and early failure of axle unit.

4. Sun shade. The sun can be brutal here in Arizona, especially to a pasty Scotsman like me.

5. Waterproofing. Even here, it rains on occasion.

6. Jack plug style socket for charging. Sooner or later I'm going to get home tired one night and connect the positive charger crocodile clip to the negative charging terminal. Changing connector to a jack plug will save me from myself.

7. Battery gauge. After all the money I've spent, this will be the cheapest, nastiest voltmeter I can find.

8. Purchase better tools. All work was done on a ridiculous 2” vice. A larger vice and a drill press would have allowed a more professional looking end result and wasted less aluminum (and flesh).

9. Low voltage cutoff relay. If I accidentally leave the motor switched on, this will cut the circuit if the voltage drops below a certain potential. This will prevent damage to the batteries.


code by jerry