Karmann Ghia EV Conversion - Speed sensor problem / New gauges

I have come to the conclusion that I will not be able to get the WarP motor speed sensor kit to be compatible with the Synkromotive controller. There is a glitch that arbitrarily limits motor RPM to approximately 3600. The sensor seems to display RPM accurately.
Since I could not fix this problem, I decided to by a 52mm tachometer which will fit in the dashboard in place of the original clock. This will not prevent over-revving the motor but should give satisfactory feedback to the driver to avoid damage.

Tach from amazon

I installed it in the hole for the clock on the dash and it works nicely.

I ended up not liking the appearance of the amazon tach. Instead I bought matching gauges for RPM and Voltage from VDO. I like that the gauges match and they look similar to the original equipment. VDO makes the original gauges for the car. The other nice thing is the gauge light comes on with the headlights, not all the time, and it is attached to the main dimmer. It all works together nicely.

Karmann Ghia EV Conversion - Ground Isolation

Proper Isolation of High Voltage System is CRITICAL!

I don't think there is enough information on how to isolate the 12 volt vehicle ground from the high voltage battery pack. When I set up the high voltage system, it was completely isolated from the vehicle electronics by design. The DC/DC converter is one area where the two systems interact, the model I used is an isolated model. The error I made was with the Xantrex battery monitor. It does not isolate the 12 volt negative from the high voltage negative and neither does the voltage prescaler that is required to measure voltages greater than 36 volts.
I figured this out the hard way when I mildly electrocuted myself by touching the chrome bumper with my body while touching the motor which had a residual charge with my arm. At that point I realized that there was a problem. If the systems are isolated, there will be virtually no voltage between the the voltage positive and the body of the vehicle (ground). I traced the problem to the battery monitor. As it turns out, there is an inexpensive and simple solution. It is an isolated DC/DC converter power supply which outputs 12 volts and 1 watt. I bought it on ebay for $6 from China. Unfortunately I had another incident where a tool I was using to secure the high voltage battery shorted to one of the battery leads from the vehicle chassis. This sent current through the battery monitor frying it.

Isolated power supply: DC-DC Converter Isolated Power Module In 10-16V Out 12V DIY Favor

 This type of isolated power supply is a MUST for your EV conversion. It improves the safety of the system and prevents damage to your 12 volt system by a short circuit. You should test your system with a voltmeter to make sure it is truly isolated. There should be no significant voltage when you test the high voltage battery positive and the vehicle ground with a voltmeter. If it reads a high voltage value, you should find the area where the systems are in continuity and isolate them properly.
While we are on the subject of safety, be sure to add as many fuses as you need. Any area where the high voltage system is connecting to something should be fused and the fused should be properly rated for the expected load. For example, the load to the controller may be 400 or 600 amps. The load to the DC/DC converter may be 15 amps and the load to the voltmeter may be 1/2 amp or less. You may also want to place fuses between the batteries especially if they are in separate areas of the vehicle.

Fixing mechanical problems with VW Karmann Ghia EV Conversion - in progress

I took the car out for a first run last week and noticed a few things that need attention.
1. Speed sensor/RPM problem\
2. The rear of the car is about 1.5" too low
3. The transmission is very difficult to shift, very sloppy

I will leave the speed sensor issue for a later post.

Its hard to say how much additional weight is on the rear. I took out the motor and exhaust system (approx $250 lbs) and added 240 lbs of batteries and a 150 lb motor in addition to wires and small electronic accessories (estimate 30 lbs). So I estimate that The rear is 160 lbs heavier than before. This weight compressed the suspension and it is now too low. I ordered Coil Over Shocks and will install them to try to bring the rear up to normal height.

With regards to the sloppy shifter, I read up and found that this is very common on old VW's. The shift rod connects the shifter up front to the transaxle in the rear. There is a shift rod bushing and a hanger up front which seems to wear and break frequently. There is also a shift coupler in the rear  which can also wear out. In my vehicle the bushing was destroyed but the coupler was intact.

Here is my coupler:

It looks pretty good.

This video shows the metal hitting metal from the destroyed bushing up front:

This is what a new bushing kit looks like on amazon:

Once it arrives i will install it and hopefully shifting will be a lot easier.

Preliminary Wiring plan and implementation Karmann Ghia EV Conversion

Before wiring everything together, I researched the proper circuit diagrams. I used the Synkromotive manual along with a diagram published by EV240Z here: http://ev240z.blogspot.com/2014/01/dc-battery-charging-through.html. I bought two screw terminal block strips with 8 positions each to connect the wires from the controller to the various components. The Synkromotive controller has 23 connections but they are not all used so 16 terminals should work.

Here is a page from the Synkromotive manual that I marked up. 

Here is a circuit diagram showing the connections to each of the 8 terminal blocks with numbers on the left side corresponding to the port number from the controller.

This circuit diagram shows the DC relay and 12 volt battery

This circuit diagram shows all of the major components.

I will need to locate some of the existing wires from the VW to connect to the terminal blocks. There is a continuous power line that runs to the ignition switch and there is a line coming back from the ignition switch when it is turned on. There is a relay wire which is powered when the key is turned to on. The chassis ground also needs to be connected. Other wires which need to be located are the reverse light and the brake light. I bought an enclosed DPST switch to activate the charging function.

Here is the front (Chevy Volt) battery. I drilled a 1.25" hole (with a 1.25" bimetal hole saw) where the right side steering column would go and tunneled the wires through. I used 1" Conduit Chase Nipples and locknuts to surround the wires as they pass through the sheet-metal. Once the wires are passed, I will reinstall the gas tank floor so that it can be used for storage or luggage.

Here is a work in progress view of the wiring of the Synkromotive controller to all of the contactors and the motor and other items. The battery and D/C converter are on the left side as is the wiring to/from the ignition key and existing car fuses. On the right side there are the charging contactors and 12 volt power supply for charging. The service disconnect switch is all the way on the left side. You can also see the battery cables pass through the firewall through a 1" Conduit Chase Nipple and 1" Locknut on the left upper corner. The battery terminals are covered in tape to prevent inadvertent contact and electrocution or shorting.

This view shows the area of the original car wiring, the 12 volt battery, the DC converter and transfer switch. Once all the connections are made and tested I will clean it up.

Karmann Ghia EV Conversion Parts List - In Progress

Parts:

(view all parts from available from Amazon here: Karmann Ghia EV Conversion Parts List)


Chevy Volt Battery pack
13 14 15 CHEVROLET VOLT LITHIUM-ION VOLTAGE BATTERY 16 KWH PACKAGE OEM J from eBay

Junkyard
$1200

Motor
Netgain Warp 9 EV DC
WarP 9 EV Motor Electric Car Motor 72V DC Motor Netgain Motor New ECPC USA Stock from eBay

ElectricCarPartsCompany.com
$2000

Controller
Synkromotive DC 750 DC Motor Controller
Private party
$1350

Speed Sensor
WarP Motor Speed Sensor Kit
EVSource.com
$99

Throttle
WarP-Drive Hall-Effect Cable-Pull Throttle
EVSource.com
$225

Adapter Plate & Shaft Coupler

Wilderness EV (I do not recommend)
$500 plus cost to make it work properly

Contactors (3)
Gigavac GC200-MA EV Contactor
Gigavac Contactor GV200MA 500+Amp - 12-800 Volt DC -12/24 Volt DC Coil from eBay
EVSource.com
$112 each

Gigavac P105 Mini-Tactor Contactor Relay - 1200 Volts
EVWest.com
$49

Fuse & Holder
Ferraz A30QS500-4H - Ferraz Shawmut 500A 300VDC Fuse w/ Holder
EVSource.com
$91

Ferraz Shawmut A15QS400-4 Fast Acting Current Limiting Semiconductor Fuse (for connections between batteries)
eBay
$30

Ferraz Shawmut ATM5 High Voltage Low Current EV Fuse 600 Volt 5 Amp(for connection between battery pack and DC/DC converter)
eBay
$5

Ferraz Shawmut Rail Mount UltraSafe Fuse Holder High Voltage Low Current (for the ATM5 fuse)
eBay
$4

8 Gauge AWG Inline Maxi Fuse Holder with Waterproof Cover (5/pack) (for 30-40 amp fuses on the 12 volt circuit)
eBay
$13

10 NEW MAXI Car Truck Boat RV Fuse 20,30,40,50,60 AMP (for MAXI fuses)
Amazon
$5

Beetrie 110pcs 5x20mm Quick Blow Glass Tube Fuse Assorted Kit Amp 0.2A 0.5A 1A 2A 3A 5A 6A 8A 10A 15A (forlow current fuses to controller)
Amazon
$6

DIGITEN 5x20mm AGC Fuse Holder Inline screw type with 16 AWG wire (Pack of 10) (for tube fuses)
Amazon
$7

Bussmann ATC-15 Auto Fuse 5-Piece (for 12 volt connections)
Amazon
$5

Parts Express ATC/ATO Water-resistant Fuse Holder - 10 AWG (for ATC fuses)
Amazon
$8

DC/DC Converter
400W 30 Amp Isolated 108-216 Volts (ECDC-HV)
EVWest.com
$229

Gauge
Xantrex Linklite (NEEDS PRESCALER!)
$210

Pre-Scaler
Increase E-Xpert Pro Voltage Input To 350VDC - Passive
EVSource
$56

Inertia Switch
First Technology Inertia Switch
EVWest.com
$53

Disconnect Switch
Gigavac Maintenance Switch HBD41AA 1000V 400A Continuous Hermetically Sealed (Main Switch)
EVWest.com
$78.00

12 Volt power supply (for charging the battery) - HP Proliant DL580 G5 438202-002 DPS-1200FB 1200W Power Supply
HP Proliant DL580 G5 438202-002 DPS-1200FB 1200W Power Supply from eBay
$30 x 2

Charger
ElCon PFC 2000+ Battery Charger (120volt/20 amp)
EVSource.com
$665

LED Replacement Lights:

Headlights
7" Crystal Glass/Metal Headlight CREE SMD COB 360° LED Light Bulb Headlamp Pair - on eBay
eBay
$126


Sidemarker bulbs OE-1895
LUYED 5 x BA9s 3014 30-smd White Color BA9 BA9S 53 57 1895 64111 LED Bulbs used for side door courtesy lights,Map Lights
Amazon
$12

Brake light bulbs OE-1157
LUYED 2 x 800 Lumens Super Bright 1157 2835 33-smd White Color 1157 2057 2357 7528 LED Bulbs used for turn signal lights ,tail lights
Amazon
$13





Misc Parts:
2/0 AWG Wire: 25' 2/0 EXCELENE WELDING CABLE RED USA NEW BATTERY from eBay
1/0 AWG Wire: 0 Gauge 25’ Wire UltraFlex Amplifier Red Ga 1/0 Amp Power/ Ground Cable 25 Ft from eBay
2/0 Wire Lugs 1/2" and 3/8"
10 AWG Wire: Monster Cable 100% OFC Copper 100Ft 10 AWG Gauge Power/Ground/Speaker Car Wire from eBay
M6 threaded rods
3/8 Nuts and Bolts
M10 Bolts
#10 Nuts and bolts
Fuses: Bussmann ATC-15 Auto Fuse 5-Piece, Ancor Marine Grade Electrical Fuse,
Fuse holder: DIGITEN 5x20mm AGC Fuse Holder Inline screw type with 16 AWG wire.  Parts Express ATC/ATO Water-resistant Fuse Holder - 10 AWG 
Resistor: E-Projects 10EP512100K 100k Ohm Resistors, 1/2 W, 5%
12V 18AH SLA Battery - ExpertPower EXP12180 12 Volt 18 Ah Rechargeable Battery with Nuts and Bolts
Welding wire:  INETUB BA71TGS .035-Inch on 2-Pound Spool Carbon Steel Gasless Flux Cored Welding Wire
Eye bolt to lift motor: Mintcraft LR287 1/2-Inch X 4-Inch Zinc Eye Bolt with Nuts



Tools:
Cable Cutter
Jonard JIC-63050 High Leverage Cable Cutter with Red Handle, 9-1/4" Length


Hydraulic Crimping Tool
8 Ton Hydraulic Wire Crimper Crimping Tool with 9 Dies Battery Cable Lug Terminal Electrical Crimping Tool Kit


Center Punch
TEKTON 6580 Automatic Center Punch

EV Conversion: Throttle installation -- connect throttle cable to cable pull throttle

71 VW Karmann Ghia EV Conversion

A gasoline engine has a throttle which controls engine speed. The accelerator pedal pulls on the throttle cable which is typically connected to the carburetor. For an electric conversion, this cable has to pull on a device that signals the controller as to the pedal position. I used the WarP-Drive Hall-Effect Cable-Pull Throttle. This device was tricky to mount because there was nothing to attach it to directly. I bolted a piece of bar steel to the firewall and bent it 90 degrees to serve as a mount for the throttle. I routed the cable through it and used a cable stop to hold it in place. Here is a video of the test run of the throttle.

Rear Battery Installation - Chevy Volt batteries - VW Karmann Ghia

71 VW Karmann Ghia EV Conversion

I decided to do something a little custom to mount the batteries. (I am using Chevy Volt batteries for this project.) 13 14 15 CHEVROLET VOLT LITHIUM-ION VOLTAGE BATTERY 16 KWH PACKAGE OEM J from eBay I probably could have strapped them on top of the rear engine compartment deck and put one or two in the front trunk as others have done. I have see other installations that put the batteries in the area where the rear seats would be. I wanted to accomplisth 2 things with battery placement. 1 not loose seating capacity (keep the rear seats), and not increase the center of gravity or cause too much rear weight distribution.

I decided to drop two of the battery boxes below the rear engine compartment on either side of the electric motor. They are to be approximately as low to the ground as the ICE was before it was removed. I am planning on putting one box in the front cargo area and putting the other remaining box (4 total) above the electric motor in the rear. This plan keeps the center of gravity low while distributing some of the weight forward. This should result in good driving dynamics.

To accomplish this plan, I cut out sections of the rear engine compartment floor with an angle grinder and custom fabricated hangers to hold the battery boxes out of 3/16" x 1" steel bar and M6 threaded rods. I had to reinforce the rear part of the engine deck with welded struts to support the weight.

Rear engine compartment showing space to left and right of the motor where the sheet metal will be cut out to fit the battery boxes.The rear lid was removed to place the motor.

This shows the sheet metal cut to fit the batteries on the right-hand side.

Custom welded battery hangers/ These attach to the batteries using the M6 threaded rods and bolts.

I had to reinforce the rear deck. I welded some pieces of 1/8" steel bar to improve the structure.

This shows a view from underneath the rear deck. Steel struts have been welded to support the batteries.

Here is the final picture showing both rear batteries installed.