interiorUnder hoodFront cell boxcontroller and fanmid box
OwnerTom
LocationReno, Nevada US map
Vehicle2001 Suzuki Swift
3 door hatchback
Motor AC50 3-Phase AC
HPEVS AC50 motor, 67HP peak at about 3900 rpm with 115V pack
DrivetrainOverall gear ratios (including rear end): 13.45, 7.16, 485, 3.45, 2.88
ControllerCurtis 1238-7501
max current 550A, max voltage 130V
Batteries36 Skyenergy 180Ah, 3.20 Volt, Lithium-Ion
36 LiFePO4 cells connected in series, nominal voltage 3.2V
System Voltage115 Volts
ChargerManzanita Micro PFC30
43A AC Max input current at 240VAC, max output about 38A DC at 120VDC. Typically charge at 32.5A AC (30A DC into pack) at home. Just plug in when done with the car for the day, and go in the house. Usually takes 2 to 3 hours to charge, a bit over 4 if discharged 70%.
HeaterFarnam heater pads and controller (kta-ev), 10 total. Work very well, kept cells at the 59F (15C) setpoint on two successive nights at -5F (-20.5C). Slow to initially heat though, about 3F/hour increase in temp. Cells in steel boxes with 1/2" polyurethane insulation. This has a very significant impact on range and voltage sag in a cold climate in winter. I see about a 25% difference in range winter to summer with the heaters set at 60 F (16C). In winter the cells typically remain at 50 to 70 F, with ambient of around 20 F (-7C). At 80 F (27 C) ambient, they get up to 90-95 F (~34C) and have lower internal resistance and more capacity when charged at this temperature. I had to tweek the voltage limit on the charger to get a full charge in summer due to the lower ir of the cells. If the cells are unheated in winter, range will suffer significantly. The heaters are only on when the car is parked and plugged in. They will remain above 50 F for around 4 hours at 20 F ambient, when parked outside unplugged after a 10 mile drive.
DC/DC Converter TDC-120V/12V
The 400W "no name" sold by Cloud Electric
InstrumentationCurtis 840 gauge, displays battery voltage and (estimated)current, motor and controller temperatures, motor rpm. TBS E-xpert Pro gauge, displays battery voltage and current, SOC, Ah used, has low SOC, low voltage, high voltage alarms. Great gauge! Works just like a fuel gauge. I have been running the car with only this, no bms, as the cells remain balanced to within less than 4mV of each other typically, and I stop at 30% SOC.
Top Speed90 MPH (144 KPH)
Calculated. Has pep in 4th gear at 75mph, so I think it will do 90 easy.
Acceleration0-60 in 16 seconds, 1st through 3rd gear.
RangeAll at 80% DoD: 97 miles at 30mph, 76 at 40, 58 at 55 - Estimated by averaging current draw driving both directions on a stretch of road, dividing into 0.8*180Ah, and multiplying by the speed. Generally about 65 miles at 50%/50% highway/secondary road driving, 55-60mph highway, 70% DoD.
Watt Hours/MileAbout 205Wh/mile cruising at 50mph. 200 to 210Wh/mile with mixed highway/secondary. Update: Drove 65 miles round trip on 1/5/10, most at 50mph, rest 35 to 45mph. Used 114Ah and about 200Wh/mile. Update 6/10: Better range in warm weather, about 80 mile range now in mixed driving, around 180 Wh/mile or less.
EV Miles
Current:2,500 Miles (4,022 Kilometers)
Seating Capacity2 adults
Curb Weight2,250 Pounds (1,022 Kilograms)
Everything stock, including all suspension (only about 350 lb over original curb weight)
TiresMichelin radials (on donor)
Conversion TimeAbout 4 months
Conversion Cost$2700 for donor, about $20k for rest
Additional Features1/8" poly from front bumper to just before front axle to protect motor from water and gravel. Bilge blower (150 cfm) to ventilate mid and rear cell boxes. Axial fan (250 cfm) to cool controller - necessary to drive at highway speeds continuously in summer, or maybe big finned heat sink - update 6/10: added 10"x11" heat sink with 2.5" fins. Controller now remaining below 45 C typically in 80 F (27C) ambient. Update 6/10: cells still not going above 90 F yet in 80 F weather and no blower. Added Dimitri's minibms, sans shunts, several months ago and it works well. But now that I have the charger voltage limit tweeked in it stops charging at about 3.44V/cell every time, so the minibms is just there as backup. I set it this way so cells are charged to the start of the exponential rise part of the V versus Ah or time curve. All 32 original cells remain balanced typically to within 2 mV of each other after charge. Replaced 4 due to over-discharge by a different bms, and have balanced (individually charged) these twice in about 5 months after they became unbalanced by about 0.01 V from the others.
More details at "SwiftE" thread under Builds and Conversions forum on the diyelectricar site. Also in the "garage" at that site. An Excel spreadsheet (referred to as "ev calculator") can be downloaded at electricnevada.org. It described this car's performance very well after modification for 115V pack (gives 90lb-ft torque out to 3900 rpm), from the test data for 96V pack in the standard spreadsheet. Largest error about 5% for predicted range and current draw at various speeds, and Wh/mile. Update 6/10: the error for range is even larger for summer operation due to larger cell capacity and lower internal resistance at higher temperature. I have not re-measured current draw at various speeds at summer temperatures to see if they are significantly lower, and account for the error.

Regen was set up lower than I liked on the system as shipped. Had to use mechanical brakes more than I wanted on hills and had max of 15A to 20A regen. Purchased a programmer and changed this so now get up to 190A regen and don't have to use mechanical brakes on most hills. Control amount of electric braking by easing off accelerator pedal, and if necessary by shifting (same as "engine braking"). Control of vehicle speed is mostly by the right foot. Can stop for a light using only electric braking most of the time, by easing off the accelerator more and more as I approach the light. A very reliable car. Just get in it and go. Plug in when done with it for the day, and go in the house.

code by jerry