interiorcabin heaterFront cell boxController mounted on heat sinkmid boxJ1772 charge plugUnder hood
LocationReno, Nevada United States map
Vehicle2001 Suzuki Swift
3 door hatchback
Motor AC50 3-Phase AC
HPEVS AC50 motor, about 64HP peak at about
3900 rpm with 36 cell nominal 115V pack
DrivetrainOverall gear ratios (including final drive ratio of 3.79):
13.45, 7.16, 485, 3.45, 2.88
ControllerCurtis 1238-7501
max current 550A, max voltage 130V
Batteries36 CALB/Skyenergy 180Ah, 3.20 Volt, Lithium-Ion
36 LiFePO4 cells connected in series,
nominal voltage 3.2V per cell.
System Voltage115 Volts
Charger EMW 12kW
Max output current is about 80A DC, from 240VAC/50A outlet. Pack V ~ 122 to 126V during charge at this current. (126 is CC/CV transition, holds between 124-125 after that). About 11kW from wall, 10kW into pack, max.
HeaterCabin heater: two 1.5kW ceramic heater elements mounted side by side in teflon fixture and inserted in place of original heater core. Gives about 3160W with blower on high. Warm air starts coming out about 8-10 seconds after turn-on. Usually only leave on for <10 minutes at a time when around 20-25 F outside or cabin gets too warm.

Battery heaters: Farnam heater pads and controller, 10 total. Work very well, kept cells at the 59F (15C) setpoint on two successive nights at -5F (-20.5C). Slow to initially heat up, 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 20%-25% difference in range winter to summer with the heaters set at 60 F (16C) due to stiffer drive train and cabin heater use. In winter the cells typically remain at 50 to 70F, with ambient of around 20 F (-7C). If the cells are unheated in winter, range will suffer significantly. The heaters are only on when the car is parked and plugged in to 120VAC. 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
Hangzhou Tiecheng Information Technology Co., Ltd 400W isolated. Purchased from Cloud Electric in 2009.
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 ran the car with only this, no bms, for about 3 months, then added minibms.
Top Speed95 MPH (152 KPH)
Calculated. Has some pep in 4th gear at 80mph, so I think it will do 95.
Acceleration0-60 in 16 seconds, 1st through 3rd gear,
measured with gps data logger.
Range75 Miles (120 Kilometers)
Generally get about 75 miles at 50%/50%
highway/secondary road driving, 60mph
highway/35 mph secondary, 70% DoD in
summer. Winter range more like 60 miles due to stiffer drive train and heater usage.
Watt Hours/Mile200 Wh/Mile
Average from the wall socket, including
all losses, over the first 4 years of operation was 215 Wh/mile. Measured
with EKM meter. Typically use around
170Wh/mi at around 35 mph, and around
240Wh/mi at 60 mph, both on fairly
level/rolling terrain in summer.
EV Miles
Start:83 Miles (133 Kilometers)
Current:135 Miles (217 Kilometers)
Total:52 Miles (83 Kilometers)
Seating Capacity2 adults
Curb Weight2,260 Pounds (1,027 Kilograms)
Upgraded rear springs by 270 lb in 2013 to correct rear camber.
Conversion TimeAbout 4 months (after about 1 yr of study, calculations, and searches on parts)
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.

Axial fan (250 cfm) mounted on 10"x11" heat sink with 2.5"
fins to cool controller - necessary to drive at highway speeds continuously in summer. Controller has remained below 67 C in up to 100 F ambient.

Marinco 50A charge plug under hood, J1772 where gas cap was. 50A DPDT relay with 240VAC coil automatically connects charger to whichever receptacle receives power.

More details at "SwiftE" thread under Builds and
Conversions forum on the diyelectricar site. Also in the
"garage" at that site.

Purchased the Curtis PC programming sofware to adjust controller parameters. Set max ~ 150A regen (limited by brake map parameters). Use mechanical brakes very little.
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. Hot tub timer connects power to the EMW charger at midnight, turns it off at 4am.

Total ev miles: 7471
Total kWh used from wall outlet (EKM meter): 1615
Average Wh/mile: 216 (from wall, per EKM)
Maximum distance driven between charges: 75.1 miles, much
at lower speeds so only 64% DoD. Roughly half of miles were driven at 50-60 mph, half at 30-40 mph. Maybe 1/4 of trips with bike on back and mostly highway driving (higher drag).

Recently changed motor max speed to 8000 rpm from factory
setting of 6500 (HPEVS said no problem).
Now can go to about 35 mph in first gear and 70 mph in
second gear.
Update: After input from others, I decided it is likely
not good to run the transmission at such high rpm for
sustained periods of time, so now only drive in 2nd gear
up to about 50 mph (< 6000 rpm). Cells still behaving
the same, no problems with them.

Update 4/30/11: 10,053 ev miles and 1 yr 5 months in
service. See comment on Wh/mile in the Watt Hours/mile
section above. Added shunts to the minibms boards and
top balanced pack a few months ago. Working very well.
Got about 70 mile range in winter, almost same as summer, when cabin heater not used (cells heated to 65F when garaged). About 60 mile range if cabin heater is on much of the time (two 1.5kW ceramic heaters in parallel).

12/5/11: 2 years operating as an ev now. 14,617 ev miles,
3159.81kWh energy used from the wall (EKM reading),
216Wh/mile from the wall. No issues over the past year,
no down time.

Total EV miles: 22,456
Total kWh from wall (EKM meter): 4861.89
Wh/mile: 216, from the wall, around 200 Wh/mile excluding charger losses, about the same it has been each year.

Only one issue this year. A battery heater failed open circuit this fall. It was the one under the cell group that had the heater controller thermocouple on it, so the rest got heated to around 100 F before I discovered it next morning. No damage done.

Decided to check and redo all heaters. Made aluminum pans that fit tightly into the boxes against the insulation, with heaters taped to the bottom of the pans under each cell group with aluminum tape. bolted aluminum angle to the top side of the pans to help hold the cell groups in position. Strapped cells down tight, nothing seems to be moving over the last few weeks. Heaters should be ok now without the cell ribs scrubbing on them.

Also added 86F N.C. thermal switches, one in each battery box, mounted to a cell terminal on a tab. Wired AC supply to heaters through them. There can be up to 21 F difference in open/close, and operating temperature is only accurate to +/-5F according to documentation. At least one seems to be opening at high 70's and it appears all are not closed until around mid 70's F, which is fine since I am using a heater controller setpoint of 65 F now. Should be no more overheating if the tc fails or the heater fails again.

No noticeable change in range. Only test I've done is the usual drive to around 28-30% SoC, then floor it to draw 550A (3C) and see if the minibms LVC alarms (threshold 2.8V for 4 seconds). Never has so far.

Other than that just drive, charge, drive, charge...

Total ev miles: 29,148, 211 Wh/mile ave from wall socket this year, bit less than 200 Wh/mile excluding charger losses.
Did some upgrades:
1) EMW charger, can charge at up to 10kW now in cool weather, around 6kW in hot weather (inductor overheats).
Update 3/2014: New output inductor - remains less than about 25C above ambient at 70A charge current, heat sink temp is now the limit for max power in hot weather (about 32C above ambient at 70A). Think will be able to do ~6kW in 90F ambient, will see.
2) Installed J1772 in gas port, and Marinco 50A plug under hood.
Replaced minibms main board (third time)for the usual reason, quad comparator chip failed. New board was redesigned to increase noise immunity, we'll see. No other issues this year. No noticeable change in range or performance. Still using the original 12V accessory battery that was in the car when I purchased it.

Total EV miles: 37,337
Total kWh from wall (5 yrs, EKM meter): 8206
Wh/mile from wall this year:236
Wh/mile 5 year average: 220

Got cheap "City Star" tires from Les Schwab this year and noticed my range decreased a bit from what I had with Michelin X tires. Also doing more highway driving/longer trips now that there are more charging stations around 50 miles from home. These two may explain the higher energy/mile this year.

Over 200 charges on EMW charger without problems (replaced Manzanita PFC30 with it about a year ago).
Over 830 charge cycles total.

No noticeable loss in range, no problems.
Same motor, controller, batteries, DC/DC, relays, etc for 5 years.

code by jerry