Results tagged “Boxer” from The GPSy EV Project

I have the Prius NiMH batteries installed and test drove it but the snowstorm of 2009 has put the dampers on harder testing. In any case, here's the new revised bill of materials (BOM) (dated 2009.12):

Base Unit	Piaggio Boxer (1971) - 50 cc 2-stroke internal combustion engine (removed)
Electric Motor	HXT 80-100-B 130Kv Brushless Outrunner from United Hobbies - link to new version of motor - Tachs: 5600 rpm @ 43.2v nominal (4500 rpm @ 36v; 6000 rpm @ 48v) - Max amps drawn: 100A @ 43V - Max watts drawn: ~ 4300 watts - Speed: 45 kph top speed (at current gearing)
Electronic Speed Controller	Castle Creations Phoenix HV-110 (link) - 110 amps @ 50 volts limit
Throttle	Magura 0-5K Potentiometer motorcycle twist grip throttle
Servo Tester (Pot to ESC)	Boman Industries Polar-Matic PC-50 (ebay)
Power Monitor	Cycle Analyst (link)
Batteries	Currently SLA: Prius Gen 2 NiMH - 6S2P packs (12 in total) - 43.2 volts nominal @ 13 Ah - 330 watt-hours (conservative) - Range: unknown
Power Connectors	- Anderson PowerPole 75A on main connections - link - Anderson PowerPole 30A on sub connections - link
Wiring	- 8 gauge stranded copper on main power lines and motor leads - 12 gauge stranded copper on sub power lines
Lighting	- Front lighting using high-power Luxeon LED - Rear lighting using high-power red LEDs
Low Voltage (12/5VDC) Converters	12VDC converter using National Semiconductor LM2576HVT-12-ND buck-converter for motor cooling fan, front lighting (via 5vdc) and rear lighting 12 volt to 5VDC converter using MC34063 Based Switching Regulator for front lighting Another 12VDC converter using National Semiconductor LM2576HVT-12-ND buck-converter for ESC controller cooling Quark Pro BEC 3A UBEC for servo tester / RC components
Things I burned out/destroyed	E-Sky EK2-0907 Servo Tester Doc Wattson power monitor ELF 100 ESC speed controller Castle Creations Phoenix HV-110 Right index finger on burnt out ESC Various burns and scrapes

This is the post-flameout, rebuilt Piaggio Boxer EV. I changed the battery carrier from a top-mount system to saddle bags. This lowers the center of gravity and makes it easier to handle. I'm going to replace the seat with something more classic looking.

I welded the saddlebag carriers myself from steel tubing with my MIG welder.

The Electronic Speed Controller (ESC) is sitting on top. It's the replacement HV-110 that I received from Castle Creations with additional capacitors soldered in parallel on the input lines.

It's sitting in a Lexan enclosure that I bodged together. Unlike the old metal enclosure with a single temperature controlled fan, the new enclosure uses two fixed speed fans that pull the air across the ESC and the voltage converters (sitting below). They also are assisted by draft air when the vehicle is at speed.

This photo was taken a few minutes after a short run, the temp of the caps is 34 centigrade which is nominal. Anything less than 60 centigrade I think will be ok. The caps are rated at 85C.

Although the angle of the photo above makes it look like the ESC could short out on the voltage converters, it's actually held a centimeter or so above and everything is well insulated.

My replacement servo-tester finally came in yesterday. I immediately tore it apart and replaced the potentiometer in it with a cable so that it could plug into my Magura throttle. The design of this replacement looks very simple. All discrete components: a 555 timer IC, rectifier, and some caps. I think I'll try to reverse engineer it so that I can just build it myself next time.

While I was waiting for the replacement to arrive (two weeks!), I took my Boxer almost entirely apart and placed the ESC and other electronics in the compartment where the old gas tank used to be. I also made a pannier for the batteries on the side. The result is a pretty clean ride:

The bike is very stock looking, which was one of my key goals. From the outside, the only indication that it perhaps isn't gasoline powered are the two SLA batteries in the panniers. The only real work that needs to be done is to clean up the remaining wiring for the servo-tester / throttle.

This is a neighborhood kid who helped me make the battery carrier. He insisted on being in the photo.

I'd like to revise the battery carrier to be a little more stealth. This first version was just a hack-up to get the things mounted.

Right now I only have batteries mounted on the right side. Two SLAs (2 x 12V = 24V @ 18 Ah) give me a top speed of 30 kph (20mph) which is just fine for the type of intracity commuting that I made this bike for. The bike has such good starting torque that it's low max speed isn't that noticeable.

I originally planned to mount a third battery or perhaps fourth on the left side. However, two batteries are giving me the speed that I want so I might put a regular pannier on the left so that I can carry groceries.

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The following are some screen shots of the CycleAnalyst after my first test ride in this new configuration.

My range was 6.5 km on almost fully recharged batteries. This surprised me. I only pulled out just over 7.5 Ah before the batteries died. The batteries are rated at 18 Ah (20 hr) nominal and around 12Ah (1 hr). I was sucking juice out of them pretty fast, still I expected a little more capacity.

The Wh/km of this bike is excellent as it's very light and not all that fast.

The speed here is given in km/h. So that would be around 20 mph max and 15 mph average.

The batteries were seemingly dead at the end of the test run. As you can see, Vmin was 15 volts (this includes voltage sag/drop from power use) which was causing my CycleAnalyst to reboot sporadically and the ESC to cut in and out. Very bad.

Yet when I hooked the SLAs back up to my smart charger, it said that they were 42% full. Which is about right as I pulled 7.5 Ah out of an 18 Ah battery. Still, there was really no juice left in them. Maybe if I had let them rest a little bit, I could've gone a few more kilometers.

I'm trying to figure out what to do. The max speed is fine but the current range is a bit lower than what I had wanted. I wanted a range of around 12 km so that I could go to work and back without recharging. Some people mentioned that AGM SLAs take a while to "break in" so I guess I'll try to see if that's true and if performance gets better as time goes along.

p.s. Just a side note, Amax was 129 amps @ 24 volts = 3000 watts or 4 electric horsepower! This was just starting torque, when I was cruising it was sipping around 300 watts to keep me going.

At the current moment, I have the ICE engine out and the Razor motor in and wired up. Using a small hub on the 250 watt motor, I'm getting about 5-8mph and not nearly enough power to make it up hills. Fortunately, this was designed as a moped and I can pedal assist whenever I need to. Also, the centrifigual clutch means I can't stall out the motor.

The problem is that I don't have enough power, the motor is running very hot (70 C after 10 minutes runtime), and the rinky dink batteries I have now won't give me enough distance.

As mentioned above, I've ordered an HXT outrunner motor from Hong Kong (per Scott @ Endless-Sphere's experience) and will wire it in once it arrives. I'm hoping to be able to go 30 mph on straightaways if I can with larger SLA batteries on it.

This is my very high-tech throttle control. The Rocket controller is not speed adjustable, you just have to short two wires. I short one pair and turn on the bike using the mini-headphone jack on the left (aka: "the key") and then turn on the motor using the switch on the right. I avoided doing anything nicer as the HXT outrunner + ESC that I'm using in Phase 2 will be an entirely different control system.

My partner had bought an old Piaggio Boxer mo-ped a couple of years ago but sitting in our garage had rusted out the engine. I decided to make it an EV conversion.

So far, I've removed the old ICE cleanly. It looks like the ICE was connected to the rear wheel through a belt-driven CVT / clutch.

My replacement motor is a small 24V / 250 watt one taken from a RAZOR electric (toy) motorbike. It's about the only thing I can find that would fit in the small area of the former engine compartment (about 4-5" wide). If the 24V works and doesn't have enough power, I'll have to see if I can find a more powerful pancake unit or mount the motor in a separate place.

I'm driving of to my nearest (? 1 hour+) tractor supply center today to see if I can find a v-belt pulley that will attach to the motor. The old front CVT pulley from the ICE won't fit on the DC motor because the spindle isn't long enough.

IF I can find a new pulley today and find some kind of engine mount, I think I can finish up the conversion this week. But I'm just guessing at the pulley gear ratio and I don't think that the 250 watt motor will be powerful enough.

The controller is rated for 24V / 30A so I could put in a bigger motor if I could find it..... Or I could hop up the voltage to 36V by adding another L-A battery.