The Original TruckA different viewOn displayUnder the bed
OwnerJesse Tufts and John Storey-Bishoff
LocationEdmonton, Alberta Canada map
WebWebPage
Vehicle1992 Daihatsu Hijet
First Conversion, direct drive, 4x4, AC motor and Lipo4s. This is a Jumbo cab model so it actually has some usable cab space.... in that you can actually sit in it without your knees on the dash and your head hitting the roof.
MotorHPEVS AC50 3-Phase AC
DrivetrainOriginal Daihatsu transfer case, original transmission stripped bare, locked into direct drive. Stock 6.83:1 final drive ratio.
ControllerCurtis 1238-7501
550 Amps peak, 72-108V, limited to 80%, 440A to be a bit easier on the cells
Batteries24 Thunder Sky 100AHA, 3.20 Volt, Lithium Iron Phosphate
Air channels in the insulation under the battery pack allow warm air from out thermostatically controlled battery heater to circulate through the battery pack, heating it up in winter time.
System Voltage72 Volts
ChargerElcon PFC1500
Currently charging to 3.7V/cell, with a custom battery management system. BMS includes current control for the charger to actively lower the current to keep the high cell below the cutoff. This allows a complete charge and full balancing to within 2mV every time. In cab LCD shows charge current, Wh's, voltage and balancing status.
Heater2 ceramic heater cores running 72v
DC/DC ConverterElcon 30A
This keeps a small 5Ah 12V gel cell charged up when the truck is on. The gel cell just has to turn the starter relays on and will run the flashers for a while if needed.
InstrumentationCycle Analyst shows current, voltage, counts Ah and Wh and calculates Wh/km, Spyglass gauge shows motor RPM, current, voltage and motor and controller temps. BMS LCD display shows voltage, current, average cell voltage, low cell voltage and gives low cell warnings as well as regen brake light control.
Top Speed53 MPH (85 KPH)
Top speed on the flat is about 85km/hr. The motor is at 5500rpm at 80km/hr due to the small tires and high final drive. There isn't much power at that speed due to our low system voltage but its just right for the city.
AccelerationGreat up to 50km/hr, Starts falling off quickly after 60km/hr. The acceleration is decieving as it's constant from right off the line up till about 40km/hr so you get going faster than you think, lots of fun to drive! The current limit is set at 80% or 440A to go a little easier on the cells.
Range37 Miles (59 Kilometers)
Maximum range should be 60km in the city. Better than expected and work is ongoing to improve it. Got 50.5 km at mostly ~80km/hr which drew 103Ah at which point the lowest cell was hitting 2.8V with even low current draws.
Watt Hours/Mile223 Wh/Mile
Mixed city driving at ~6 degrees celsius, up and down the edmonton river valley hills a few times, cruising between 50 and 60 km/hr for 32.6km gave 140Wh/km from the pack and 170Wh/km from the wall after a full recharge. No heater use. Should get better with less hills and in warmer weather. With Alberta's coal fired electricity this puts my C02 at 150g/km which is still less than the gas truck would have produced.
*Update, warm weather flat driving in the city gives 125Wh/km, 140Wh/km from the wall. With more up to date CO2 numbers for Alberta electricity production this puts the truck at 115g/km! Much better!
EV Miles
Start:43,106 Miles (69,357 Kilometers)
Current:43,938 Miles (70,696 Kilometers)
Total:832 Miles (1,338 Kilometers)
 
    As of 10/18/2012
Seating Capacity2 adults
Curb Weight1,470 Pounds (668 Kilograms)
That is stock, should end up within 100 lbs of that haven't weighed it yet.
Tires145-75R12
Conversion Time~8 hours per week for the last 2 years, 1000 hours total including most of the design and some of the research.
Conversion Cost~$13,000 including the truck
Additional FeaturesMy friend John and I are working on this project. It is finally mostly finished and we're trying it out as a car sharing deal between our two families. We're within biking distance so moving the truck back and forth should be pretty easy. The goal was to have a usefull city runabout with all weather capability. With the original transfer case we retain selectable 4wd with low range.

Both our battery box and the cab have been insulated and during winter the battery heater and an auxilary cab heater will come on with a timer so you can get into a warm truck with warm fully charged batteries! The BMS includes an interlock to prevent the heaters from kicking in if the charger is still going in order to prevent the breaker from blowing.
Check out my blog for more pictures and updates! Link at the top.

Some cold weather testing has revealed that these batteries really don't like it below about -5 C but warming them to even above 0 deg C helps quite a bit and they really perform the best above 15 deg C. The problem is voltage sag. At a battery temp of -15C, a 50A draw caused the fully charged cells to sag to 2.7V, and the controller starts cutting out. Warming them is essential and makes a big difference.

The truck passed the safety inspection spring 2012 and its on the road! I've put several hundred km on it so far driving to work and for errands and its been a blast! Based on the current electricity price and my Wh/km from the wall my cost to drive the truck is just 1.3 cents/km.

**Aside** In terms of just cost I will burn about 70 calories walking 1 km, if I only eat rice that's about 3.5 cents/km! But I do like to eat regardless and I probably normally end up eating at least that extra 70 cal anyways so I don't think this is a valid argument for driving vs. walking or biking. That said if you have to drive the electric mini truck is a pretty efficient (and fun) way to go about it!

code by jerry