| Owner | Stewart | ||||||
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| Location | Victoria, British Columbia Canada map | ||||||
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| Vehicle | 1988 Kawasaki EX250 | ||||||
| Motor | Mars ME0709 Series Wound DC Generates a bit more heat than I was expecting. Wondering if I should have gone with the PMG132. June 2011 update: over the winter when the bike was stored the brushes seized up, so that in the spring there was heavy arcing. There was no permanent damage to the commutator. I called Mars electric and they quickly sent me a replacement brush assembly. The bike was stored indoors. The brushes seemed to have swelled. No corrosion....They are apparently working on a new brush assembly design. I'm happy that Mars provides such good customer support! | ||||||
| Drivetrain | 420 chain, 70 teeth rear, 16 teeth front. #4 wire for all high current circuits (considering upgrading to #2 from the controller to the motor) - as these leads seem to get the warmest after a spirited ride. | ||||||
| Controller | Alltrax 7234 300 Amp. This units is great! Generates very little heat, built very well, and quite small. The only thing that would be better (very minor issue) is a torque (amps) controlled speed control. This unit appears to be controlling output voltage based on throttle setting - applying up to 300amps to get you to this voltage. It's a bit unnerving on a m/c riding the twisties for the first time, as throttle control (which determines the lean angle and turning radius) is completely different than from a gas engine. I suppose the lack of engine braking also doesn't help. When riding for fun (not concerned about range) I find myself hard on the brakes much more than when this bike was gas powered... | ||||||
| Batteries | 6 B and B EV50-12, 12.00 Volt, Lead-Acid, AGM 50 Ah. Managed to squeeze them all in. Needed to widen the frame under the seat 1" and remove the bottom faring. 1st option was the 35Ah which would have easily fit and kept the overall weight to same as or slightly less than stock. Glad I went with the larger batteries - even with the weight (acceleration) penalty - for the additional range. Seriously thought about and almost went with TS-LFP60 lithium...but seemed much more complicated requiring a battery management system, and those systems that ran without seemed to have reliability issues...As with everyone - saving this upgrade for the (hopefully near) future. | ||||||
| System Voltage | 72 Volts | ||||||
| Charger | Soneil 2412SRF 6 amp, 24 volt, 3 units across 3 sets of 2 batteries in series. Note that not all Soneils can be connected in a series string like this... June 2011 update: these chargers are now mounted inside the gas tank. I've been extremely impressed with these chargers. The batteries have remained in perfect balance, and the performance now (aprox 3000km after conversion) is the same as it was when new. The bike sat over the winter and I plugged it in for a day every month or so to keep the batteries fully charged. | ||||||
| Heater | M/C gear. Heated grips will come with the cooler weather. | ||||||
| DC/DC Converter | Sevcon 622/11086 300 watts at 13 volts, fully isolated. 72- 80 volt nominal input. Very happy with this unit. Seems to operate just fine all the way down to 40ish volts. Produces very little heat. | ||||||
| Instrumentation | Everything as stock except for tach, oil pressure and temperature gauge. Plans to convert the tach to an Amp gauge. Also plans to put the temp sensor on the motor - as it seems to generate the most heat in the system. | ||||||
| Top Speed | 60 MPH (96 KPH) Pulls quite good to 50, after that, tapers off to 55 or 60 depending on riding position, incline, head wind, state of charge of the batteries. | ||||||
| Acceleration | Constant acceleration 0-50. 6 seconds. | ||||||
| Range | 30 Miles (48 Kilometers) Not fully tested yet (want to be kind to the new SLA's). Calculations show that it should be dependent on cruising speed. 30 mi @ 30 mi/hr, 20 mi @ 45 mi/ hr, 15mi @ 55 mi/hr to 70% DOD. June 2011 update: (after aprox 3000km/2000mi) I commute about 1/2 the days in the summer a distance of 22 miles both ways. 1/2 this commute is on the freeway at top speed. Chargers put back in 30Ah after this round trip. Haven't taken it much farther than this. Still has very decent performance at this point (4 mph lower top speed then when fully charged). | ||||||
| Watt Hours/Mile | June 2011 update: my 22mi commute requires 30Ah. The chargers put back in 6amps and require around 600Watts (at 120V) to do so. Working out the math this would be 136Whr/mile. | ||||||
| EV Miles |
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| Seating Capacity | 1 'normal sized' (6ft 185lbs) person, or two smaller people. (It is a small bike...) | ||||||
| Curb Weight | 450 Pounds (204 Kilograms) About 50lbs heavier than full wet weight (full tank of gas) stock. | ||||||
| Tires | Nothing special. Standard ones it came with inflated to max pressure (42/44) psi. June 2011 update: This winter I replaced the old tires which were 16- 100/90 front and 16-130/90 rear, with the correct stock size which is 16- 100/80 front and 16-130/80 rear. This size is not as common, but I found a set of Pirelli Diablo Scooter tires that were perfect. These tires are a lighter construction (2ply) and are much softer and incredibly sticky wet and dry. The handling of the bike is also slightly better with the smaller profile. Top speed was reduced very slightly but I have a 17T motor sprocket to compensate if needed. So far it has not been an issue. I'm very pleased with these tires (except that they say 'Scooter' in large letters on the side :) ) | ||||||
| Conversion Time | 6 months spare time | ||||||
| Conversion Cost | $2500 in parts | ||||||
| Additional Features | 'Neutral' with kick stand and engine kill switch lockout. Push to 'start'. Neutral light as well. Throttle disable on controller if 'started' with throttle applied. Works well at avoiding accidental power to the motor... | ||||||
| I'm very happy with the outcome. Acceleration is slow for m/c standards, but still much quicker than the normal flow of traffic. Drive train is quite torquey, can easily spin the rear wheel on dry pavement when not seated on the bike. It's a bit heavier than I expected but the center of gravity is low. With upgraded springs in the front forks (0.75kg/mm rate) handling is just like stock. No more bottoming under hard braking. June 2011 update: after 2000 miles and some minor improvements this bike is working better than ever. I'm very pleased with it. | |||||||
1988 Kawasaki EX250
“Electric Ninja”
Last Updated 06-25-2011
Copyright © 1997-2012 by Mike Chancey