Results tagged “test run” from The GPSy EV Project

The weather was finally nice enough to commute to work this week on my Piaggio Boxer EV with Prius NiMH batteries.

Here's the data from my CycleAnalyst:

	Run #1 1.18 (To)	Run #2 1.18 (From)	Run #3 1.19 (To)	Run #5 1.20 (To)
Distance	5.2 km	4.85 km	4.21 km	4.19 km
Efficiency	45.1 Wh/km	39.2 Wh/km	42.2 Wh/km	47.6 Wh/km
Energy used	234.23 Wh	189.87 Wh	176.92 Wh	199.03 Wh
Charge Used	5.90 Ah	4.28 Ah	4.01 Ah	5.01 Ah
Max Amps	106 A	101 A	91 A	101 A
Average Speed	20.6 km/h	23.3 km/h	24.8 km/h	24.1 km/h
Max Speed	36.6 km/h	40.3 km/h	39.0 km/h	36.6 km/h
Starting voltage	---	49.9	50.2	47.2
Ending voltage	43.8v	45.9v	---	44.2v
Run time	15 min	12:30	10:10	10:24

My commute is slightly uphill on the way to work and downhill on the way back, which accounts for the difference in energy efficiency going to and from work.

The bike feels much lighter than with the SLAs and faster too (even with the gear reduction) so I have to say it's an unqualified success. I just hope I can get good life out of these batteries.

After Run #4, I was in a rush and so I put the charger on and went to a talk and then came back. About 3 hours had passed and the charger had over charged the batteries. It actually wedged the battery holder apart. So I'm worried now that my batteries will be weakened -- even though most of the bulging has subsided.

I reinforced the battery holder this morning and we'll see how it holds up.

I'm still waiting for the ESC and servo to arrive (maybe early next week) for the outrunner motor, so I took the Boxer out for a test run with its temporary Razor motor and SLA batteries installed.

Piaggio Boxer
Motor: 250 watt MY1016 (from Razor Pocket Rocket)
Controller: 30A (from Razor)
Batteries: 2 x 12V 7Ah SLA (from Razor)
Front sprocket: 1.5" pulley (motor to wheel 39:1 ratio)

Batteries were fully charged and run from 26.5V down to 20.98V (under load). I used a Garmin GPS as a trip computer and a Watts Up as a battery monitor.

Trip distance: 5.8 km (3.6 miles)
Moving time: 27:26 minutes
Stopped time: 2:10 minutes
Total time: 29:36 minutes
Moving average: 12.6 kph (7.8 mph)
Overage Avg: 11.7 kph (7.2 mph)
Max speed: 17.4 kph (10.8 mph)

Total energy: 4.4 Ah
Total Energy: 0.10 KWh
Peak amps: 21.93 A
Min voltage: 20.98 V

km / kWh: 58 km / kWh (36 miles per kWh)

Final odometer reading: 1532.0 km

Thoughts:

Given that my batteries were rated 7.0 Ah (for 20h), I was pleased that I was able to get 4.4 Ah from them in less than half an hour. I think I could have eeked enother half an Ah for 5.0 Ah. The range of 3.6 miles is pathetic, but then again, I'm using 7Ah tiny little scooter batteries.

This time around, the motor didn't see to get too hot. I think it's because everything is finally breaking in, the belt seems well adjusted and it was mostly running at 10 A which is its nominal rating and only pulling 15 - 20A when it was starting off or pulling me up a hill.

The top speed of 10.8 mph and average speed of 7.8 mph is pathetic. But it's above my expectations of 5 mph. Going 10 mph on a sidewalk is just fine, but it's much too slow for a road with moving traffic, where you would want at least 30 mph.

I imagine that if I got a real 500 watt motor in this at 48 V, it would be just fine for tooling around town. But I do need more battery life, only half an hour of run time (or 0.10 kWh) isn't nearly enough. I'd like an hour at faster speeds, which would be around 10 Ah @ 48 V (0.48 kWh) which is nearly 5x my current amount.

But hey, what other vehicle gets 36 miles per kWh? :-) According to this website (http://car.pege.org/2008-fuel/kwh-mpg.htm), 36 m/kWh is equivalent to 702 MPG Miles per US gallon gasoline in city traffic.

702 MPG! Try to beat that!

I managed to shim the v-belt pulley and jerry-rig a motor mount, so I mounted up the little motor onto my Piaggio Boxer scooter, put the v-belt on, strapped the batteries on with duct tape, and shorted the throttle wires, and it ran!

The speed was horrendous, maybe 6 mph on a slight downhill and 3-4 mph on a level surface. But that's fine for the purpose of my test run.

Here are the current specs:

Base model: Piaggio Boxer Mo-ped
Motor: 24V 240 watt MY-1016 from a Razor Pocket Rocket mini-bike
Batteries: 12 V SLA 7ah x 2 (from Razor)
Motor Controller: 24VDC 30A controller (from Razor)

After running it for 10 minutes up and down the street, the motor was extremely hot, hot enough for the label to peel off. The controller was also hot (enough to wrinkle the duct tape holding it on). The batteries seemed fine.

Thoughts:

1. I definitely need to push this up to 48V so I can get more wattage at the same amperage. There's enough space on the mo-ped runners to mount 2 sets of 2 SLAs on each side.
2. The current motor mount blocks airflow to the motor. I need to mount it better so that it is in the direct air current.
3. I need to find a more powerful motor too, while I'm at it.
4. I need to figure out how to get it to be even a higher gear ratio that what I currently have. Maybe find a smaller front pulley somewhere or figure out how to mount a large sprocket on the rear and have it chain-driven.

Anyways, I'm very pleased with myself that it at least works. Smiling Now to just make it work better!

Karen

p.s. Photos to follow soon.