Motor and Adapter PlateTransmission BellhousingGoodrum/Fecther LiFePO4 BMS KitMotor, adapter and mounting.Dash Board DismantledHW 38120S Battery CellsA single 38120S cell.76.8 Volt, 50 AHr Pack Load TestThe 76.8 Volt, 50 AHr pack, Assembled
OwnerAdam E. Hampton
LocationHouston, Texas United States map
Web/EmailWebPage email image
Vehicle1990 Volkswagen Cabriolet
2 Door, 5 seater. Convertible.
MotorNetgain Impulse9 Series Wound DC
NetGain Impulse9 motor, 129lbs. Adapted
to the VW transmission using Steve
Clunn's (GrassRoots EV) adapter plate
kit. Adapted to original engine mount
with a plate and spacers made by Bill
Swann (
Drivetrain5 speed manual transmission, clutch-less
coupling to the DC motor. I only use
gears 2, 3, and Reverse.
ControllerCurtis 1231C
Curtis 1231C Controller with Curtis PB-5
potbox. 500A peak. Originally was
to current limit in the controller;
did that, now I let the controller take
it can.
Batteries120 Headway 38120S LiFePO4 (Lithium Iron Phsophate), 3.20 Volt, Lithium-Ion
This is a custom-built battery pack that
I built. The first version is
72v, 50amp-hour. It consists of 120
LiFePO4 cells manufactured by the
Chinese vendor Headway. 3.2v, 10-amp-
hour, 38mm x 120mm cylindrical cells
with screw tabbed end caps, arranged in
a ((5p)x24s) configuration. Managed by
the Goodrum/Fechter BMS kit available at and documented at endless- in the forums. This pack can
handle some serious load! 350 amps and
the voltage drop is impressively small.

20100616 Update: Adding 72 more cells in
the next two weeks to get the pack up to
8p x 24s. Makes it an 80AHr pack
instead of a 50AHr pack.
System Voltage77 Volts
ChargerZivan NG-3
The Zivan re-programmed it for me to
88.8 CC/CV LiFePO4 profile. I had to
adapt the output slightly for it to work
with my BMS.
HeaterAmbient Houston, TX air!
DC/DC Converter
eCityPower provided DC/DC converter. It
requires at least 108V to turn on, right
now I am charging the 12V system
separately from the traction pack. As of
08/2010 this is still not installed yet.
InstrumentationCycle Analyst from - Provides
digital MPH, Amps, Pack Volts, and Amp-
Hours consumed (fuel gauge). Also data
logs via USB to a computer. The
mechanical speedometer and odometer
still function.
Top Speed53 MPH (85 KPH)
Around 53mph seems to be the top - for
what is equivalent to a 72V PbA pack I am
fairly happy with that performance.
AccelerationKeeps up with traffic fine in 3rd gear,
zippy in 2nd, slow in 4th.
Range15 Miles (24 Kilometers)
15.2 miles is on the 50AHr pack. This
will go up with the second pack of
Watt Hours/Mile255 Wh/Mile
The car burns approximately 255 watt-
hours per mile with 1 passenger on the
level streets of Houston, TX. Once the
DC/DC converter is in and the vacuum
assist on the brakes is added I expect
that to get a bit worse.
EV Miles
Start:223,762 Miles (360,033 Kilometers)
Current:224,076 Miles (360,538 Kilometers)
Total:314 Miles (505 Kilometers)
Seating Capacity5 adults. Batteries are mounted in the
trunk and eventually will be moved to be
under the hood.
Curb Weight0
Currently lighter that the original
vehicle. Not much in it right now - you
can stand in the engine compartment
between the front bumper and the DC
TiresWhatever it came with. Goodyear
or other.
Conversion TimeStarted July, 2008. Very much a "spare
time" hobby. Had the first "around the
block" drive on 2009-12-06, or about 18
months into the project. Lots of hours
spent one the project - the journey is
as much a joy as the destination.
Became driveable in December 2009, as
June 2010 is driven several times a
Conversion CostDonor Car: $550.00
/Old motor: $2500
NetGain Impulse9 Motor: $1575.00
Battery Management Systems: $200.00
Battery Cells (72Vx50AHr): $2062.50
2/0 Gauge Orange Wire: $130.00
Cycle Analyst: $180.00
Battery Cells (72Vx30AHr): $1175.00
... more to come.
Additional FeaturesLithium battery pack :-)

Beyond the battery chemistry this is a fairly vanilla
Electric Vehicle conversion. Typical conservative parts:
Curtis, Zivan, Allbright contactor.
May 4, 2009: Initial post to The car is in
progress, lots of information to post. Status at this
- Pressure washed engine compartment, still oily as all
get out because the ICE leaked oil badly.
- ICE motor removed. Vacuum lines and power steering
assemblies left in tact as much as possible.
- Exhaust system removed.
- Fuel pumps and fuel lines removed.
- Gas Tank siphoned and water-rinsed for removal.
- Gas Plug/Cap replaced with 120VAC male plug end.
- Sheilded GFCI outlet and 120VAC wiring installed in
- Installed new shift-linkage connections and bearings to
replace worn components.

May 9, 2009: A couple of updates.
- Goodrum/Fechter BMS Boards are fully assembled and
- Batteries ordered from overseas with a group buy!
- Gas tank removed (had to drop the rear suspension).

June 4, 2009:
- Corrected the model of my charger.
- Contacted to see about supporting an
LiFePO4 profile on my charger.

June 8 2009:
- Shipped the charger off to Zivan for a new firmware
- Machined aluminum mounting plate for passenger side of
the Netgain Impulse 9 Motor. (Thanks, Bill!)
- Attached motor and adapter plate to transmission.
- Leveled motor and drilled level-holes for mounting
- Purchased new bolts for mounting plate side, will
install later this week.

June 9, 2009:
- Finished installing and leveling passenger side motor
mounting plate.
Only about 10
feet in the driveway, but it worked!

June 16, 2009:
- Installed the last engine mount adapters up against the
front bumper. This required grinding about an inch off
the front of the adapter plate so the slanted mounting
brace would fit in.
- Zivan USA is shipping my reprogrammed NG3 charger back
from servicing. It is now configured to match the
charging curve on my Headway cells and it will interact
with the cutoff logic of my battery management system

June 23, 2009:
- Zivan charger is back from reprogramming.
- Battery cells were confirmed on the boat from China on
- Started dissecting the steering column and dashboard.
Got to remove the heater coils and cleanup some shoddy
wiring the previous owner put into the car. Managed to
remove the airbag without exploding myself.

August 30, 2009:
- Steering column repaired and replaced.
- Built replacement power window controller (original was
- Battery cells have arrived (see pictures).
- Starting to lay out battery cells and design first
revision pack.

November 15, 2009:
- First version of the battery pack is completed.

December 3, 2009:
- Able to scoot across the driveway on battery and
controller power.

December 6, 2009:
- Maiden Voyage! Took it around the block for a few
miles to break in the pack. WaHoooo!
- Lots to do: Power Brakes, Power Steering, DC/DC,
Insurance, Registration... ugh.

YouTube videos of the maiden voyage / test run:

WebPage - 1 of 5
WebPage - 2 of 5
WebPage - 3 of 5
WebPage - 4 of 5
WebPage - 5 of 5

December 16, 2009:
- Took the car on it's first "Beer Run" last night. ~
3.5 miles.
- Insured the car! Yay!

Still much to do: power brakes, control deck completion,
steering power replacement, fix some final stuff on the
wipers. Then on to registration and inspection to be all
"Legal" and what not.

June 16, 2010:
- Installed Vanity Lights to show off pack and motor
(useful for a roadside fix, too!)
- Range tested to 15.2 miles of range.
- Cycle Analyst installed and data logging.
- An additional 72 cells are coming via UPS.

Aug 14, 2010:
- Additional cells arrive, tested, and inspected. The
are now waiting on the bench for the next plan for the
battery pack.
- Windshield was replaced last month, now we have a shiny
crack free windshield.
- Completed the vacuum-assist brakes. This is a huge
step as the parts have been on the shelf for about a year
to get this completed. I finally found the time to get it
- Re-wired the KSI lead on the Curtis to not always be
patched in with the pre-charge resistor. This prevents a
few watts of draw from the controller that were always
placing a load on the traction pack. That's where those
pesky volts were going!

ToDo: Get the car inspected :-). Merge in the new battery
cells into the pack, install the DC-DC converter. Make
some minor tweaks to the charging and BMS systems in the

code by jerry