Original ATVATV after conversion, from rearInside back battery boxInside contactor boxInside motor boxoutside of motor enclosureBelt driveFuel tank and controlsATV after conversion with no body
OwnerStuart Friedrich
LocationRondeau, Ontario Canada map
Email email image
Vehicle2004 Polaris Sportsman 500 HO
Purchased this as a running ATV. Good market
for used parts, so selling all removed parts.
MotorHPEVS AC-20 3-Phase AC
With the motor controller I am using this motor
has a peak output of 60 HP and 80 ft-lbs of
torque. This is approximately twice the peak HP
and torque of the original engine.
DrivetrainI used the stock transmission in the ATV. The
transmission is in a separate housing from the
engine, which is one of the reasons I used
this ATV for conversion. The transmission has
a high and low range plus reverse. I used a
synchronous belt drive system to drive the
input shaft of the transmission from the
traction motor. Works well and is quiet. I
have added a cover for the belt drive since
the photos were taken.
ControllerCurtis 1238-7501
It has a nominal input voltage range of 72-96V,
a 2 minute current rating of 650A, and a 2
minute power rating of 74kVA.
Batteries32 CALB/Skyenergy SE-100, 3.20 Volt, Lithium Iron Phosphate
Using miniBMS to monitor batteries. There are
18 cells in an enclosure at the back, 10 cells
in an enclosure within the front of the frame,
and 4 in front of the seat where the fuel tank
was located.
System Voltage96 Volts
ChargerDelta-Q Technologies 96V model 912-9600
This charger is mounted on ATV
DC/DC ConverterMeanwell SD-500
This converter is hooked up in parallel with 12V
vehicle battery. It comes on when either the
ignition switch is turned on or the charger is
plugged in.
Top Speed60 MPH (96 KPH)
Top speed is 35mph in low gear and 55-60mph in
high gear.
AccelerationVery fast. Not typically something you do with
an ATV, but I am fairly sure that this
conversion would beat any stock ATV in a drag
race. In low gear it gets to top speed (35mph)
in about 2 seconds.
Range30 Miles (48 Kilometers)
30 miles of aggressive off-road driving. Likely
would be much higher if driven only on the road
and did not have knobby tires.
EV Miles
Start:2,900 Miles (4,666 Kilometers)
Current:3,224 Miles (5,187 Kilometers)
Total:324 Miles (521 Kilometers)
Curb Weight900 Pounds (409 Kilograms)
Stock dry weight was 700lbs, and based on
weight of components removed and added I
estimate I have added 200lbs. GVWR is
1200lbs, so still well within GVWR after
conversion and with rider. I have put
aftermarket heavy duty springs on the ATV that
some guys use for a firmer ride on a regular
Conversion TimeSpare time over about 6 months
Additional FeaturesI also have a secondary series DC Curtis motor controller
mounted in the front of the machine to allow me to connect
electric implements (like the electric snowblower I built).
I have the controls (on/off, and speed control pot) for this
controller mounted on the ATV headlight pod within easy reach.

The motor and all the battery cells except the 4 under the
original fuel tank are in steel enclosures that I built and are
sealed well enough to withstand washing and immersion in
water while driving. The battery cells in the enclosures are
surrounded by 1/2" of firm sponge rubber to provide some
insulation and impact protection. Watertight cable grips are
used for all wire/cable entry into enclosures.

Since the motor is enclosed, I am using a boat bilge blower
to force air cool the motor within the enclosure. I mounted
three thermostats to the exterior of the motor, which turns
the blower on and increases the blower speed as the motor
gets warmer.

I have set up a push button switch (momentary on-off) on
handlebar to allow electronic reverse of controller, which
is handy for using the ATV for plowing and other jobs.

code by jerry