A Xebra 84v conversion.

OVERVIEW

Stock ZAP Xebra’s will travel at 35MPH on flat ground, and will go up to 20 miles on a charge.  Part of the appeal of the Xebra models is the ease with which they can be modified thanks to the very simple 72 volt platform they are built on.  Parts can be mix/matched and added to these little vehicles quite easily to enhance performance.  One of the most popular mods has become known as the 84-volt-conversion.  An otherwise stock Xebra will easily travel at 40MPH on the flat at 84 volts, and range increases of up to 20% have been achieved using stock batteries.

Most 84-volt Xebra conversions leave cab voltage at 72 to take advantage of the much less-expensive 72 volt components available from the golf cart industry.  The process explained here is such a conversion.

DISCLAIMER

This modification is not endorsed by ZAP, and may void parts of your warranty.  The procedures discussed here are geared toward the experienced mechanic, and assume that all standard precautions will be used when working on an EV.  Working on any vehicle can be dangerous, and if proper precautions are not taken, you may be seriously injured or killed.  These mods are NOT designed to take the Xebra outside the factory’s specifications; in fact, they can bring the vehicle into line with advertised performance figures.  If done improperly, however, they may adversely affect the vehicle’s performance and/or handling, and again, you could be killed.  This document will outline one method of performing this popular mod on the vehicle, but the mechanic performing the actual mod accepts all responsibility for results of his/her work.

PARTS LIST

A basic 84 volt conversion involves adding the following parts:

-  A battery box to securely mount a 7^th battery to the traction pack. 

-  A battery matched to the main pack.

-  A new 84 volt charger, or a charger for the added “boost” battery.  This charger should charge the boost battery AT LEAST as fast as the main pack is being charged when plugged in and should be wired in parallel with the main charger; i.e. when the vehicle is plugged in, both chargers should operate simultaneously.

-  Cables.  The new boost battery needs to be wired in series with, and behind the rest of the pack to create the 84 volt drive.

STEP ONE:  BATTERY AND BOX

Install a box to securely and safely to hold the boost battery.  Box kits are available from GPEV for both the PK and the SD.  Install a battery that is matched to the main pack.  In our experience the battery does not have to match the main pack if it is being charged independently.  In fact, practice has shown that the Guest charger normally used in our conversions is not a great match for AGM batteries.  Because of this and the fact that GEL batteries have 4 of 5 times the life of AGM, I actually recommend GEL for this 7^th slot in a dual-charger conversion.

STEP TWO: CHARGING

The stock charger your vehicle came with will not charge the new, higher voltage pack.  Your charger must be replaced with the proper sized unit or the new 7th battery may be charged seperatly with a quality automatic EV 12v charger while the original charger maintains the stock 6-pack. This new charger should be wired into the 110 line voltage or circuit breaker for the main charger so that any time the vehicle is plugged in, the boost battery will be charged in concert with the main pack.  The theory is that the boost battery will never be drawn-down or left at a lower SOC then the main pack.

FINAL WIRING

With the boost battery and charging system installed, all that is left is to wire the DRIVE SYSTEM ONLY through the new boost battery and back to contactor A.  Contactor A is where the stock machine comes off the 72v pack positive and ties into the contactors.  The cable should be removed from the contactor side, and attached to the negative post on the new boost battery.  A new cable may be needed to accommodate length.  A new cable will now be attached to the positive post of the boost battery and routed back to where the original cable connected to contactor A.

ALL OTHER WIRING REMAINS STOCK.  The original charger and PTO lines for the cab 72v power stay stock.  This results in only the controller and motor seeing the additional boost voltage.

THE VEHICLE’S DRIVE SYSTEM NOW OPERATES AT 84 VOLTS.

NOTES ON CONTROLLERS

Xebra’s equipped with Alltrax controllers may not move if the drive voltage is above 90 such as can be found after a fresh charge.  These vehicles can be wired with a switched, dash-selectable voltage system in order to overcome this brief initial high-voltage state.  See “ALLTRAX SWITCHED SYSTEMS” below.

Xebra’s using the Curtis 80v controllers have no problem with the 84v drive, and will operate normally.  Over-voltage cutoff on these controllers is 100v.

In an Alltrax controlled system the controller may be upgraded to a more robust, more powerful version to compliment the new drive voltage.  GPEV uses the Curtis 1221c with good results.  This 120 volt controller not only handles the 84v drive well, but is tunable to allow up to 400 amps to the motor giving the vehicle a tremendous torque advantage over stock.  The 1221c conversion is not recommended for vehicles that come stock with the black Curtis controller.

ALLTRAX SWITCHED SYSTEM

Many Xebra’s came stock with the Alltrax controller.  This is an excellent controller and offers the smoothest response of any of the controllers we use in the Xebra.  Because it is programmed to protect itself at voltages above 90 it is necessary to add a switching circuit for the drive voltage to get the brief false charge off the main pack before engaging the 84v drive.  Otherwise, the vehicle will not move after a fresh charge.

In this configuration a heavy-duty Albright contactor (included in “A” kits from GPEV) is introduced between the main pack and the boost battery allowing the driver to select either 72 or 84 volt modes via a switch on the dash.  The 72v coil can be driven off the 72v heater circuit.  The relaxed contactor (down position) routes current through the boost battery providing 84v power to the controller.  The energized position (up) disengages the boost battery and routes 72 volts directly to contactor A.

CONVERTING FROM ALLTRAX TO CURTIS 1221c CONTROLLERS

If upgrading from an Alltrax controller to a Curtis controller it is important to note that these controllers expect different Throttle Pot inputs.  While the Alltrax expects a 5 – 0 Ohm input, the Curtis expects a 0 – 5 Ohm input.  Reversing the Pot’s output is accomplished by switching the red for the black wire at the output harness by the accelerator pedal.

Our kits ship with a new mounting bracket for the 1221c controller.  When used on the PK, a shorter 12 volt accessory battery must be used to allow room for the larger controller to sit over the top of it.

WIRING:

The diagram below depicts a stock Xebra with the 72 volts from the pack applied to the contactor bank directly.

V84x WIRING

Note that when using a 84v qualified Controller, the traction voltage is simply run through the 7^th battery and back to contactor A.  CAB VOLTAGE AND STOCK CHARGER (not shown) ARE STILL CONNECTED TO THE 72V PACK ONLY.

V84x A WIRING

When using an Alltrax controller, it is necessary to add a switching system.  GPEV kit ”A” uses a heavy-duty Albright system that is dash-selectable.  Note that the coil voltage (dash switch) is 72 volts.  We use a lead off of the heater switch in the dash to power it.  Return the voltage to any 72v -.

Addendum A

Xebra Hatchback

There are a number of changes in the standard 84 volt upgrade on the new Xebra Hatchback.  The wiring is considerably different, and care should be taken to get the connections right if you are used to the ’07 and older SDs.

One of the biggest changes in the Xebra Hatchback v84x is that it is now 100% 84 volts, and one charger services the whole pack.  This is a change from the old “boost battery” configuration where the 7^th battery had its own charger.

On the ’08 the new battery you put in is now before the original 6-pack, not after.

DISCLAIMER:

ZAP Xebra vehicles are NOT standardized; your unit may differ from the one’s we have seen so far.  This document is intended as a rough guide, and assumes use by an experienced mechanic.

To convert a Xebra Hatchback using the GPEV kit:

1. Remove DeltaQ charger.
2. Mark all connections to the controller and remover them.  Unbolt the controller and move it over to the bracket that held the DeltaQ.  Brackets may have to be modified slightly to fit the heat sink.
3. Re-connect wiring to controller except the (B-) cable.
4. Install new battery box to the left of the contactor bank where you removed the controller.  Remove the large motor-carrier bolt and place the battery box in the space with the shorter tab over the motor-carrier bolt hole.  Replace the bolt and snug (do not over-tighten, there are rubber grommets under it) to lock the box into place.  Drill a hole in the remaining tab through the frame and secure with the included self-tapping bolt.  NOTE:  The battery box will fit most vehicles and most group-31 batteries.  On some units some modification of the tabs may be required to fine-tune the fit (Xebras can very quite a bit from unit to unit).
5.  Install new battery and tie-down in the new box.  Battery fit may be tight under rear deck lip; you may have to tilt the battery to get it under the lip.  Insulation between lip and battery post is recommended if tolerance is tight.
6. Connect former (B-) cable from former battery #1 (-) to new battery (+) terminal.  The new battery is now battery #1, and the former battery #1 is now #2.
7. Connect new 32” battery cable between the new #1 battery neg terminal and the B- controller lug.
8. The new Zivan 84v charger mounts vertically under the dash dead center.  You may have to re-route a heater hose for proper fit. 
9. Wire the DC leads with 10ga cable.
10. Use the provided 6’ patch cord to connect the charger’s AC input to the vehicle’s power port routing it through the battery bay.
11. Place the  temp sensor on top of the batteries in the center console
12. Mount the charger’s remote LED to personal preference.

Photo below shows controller bay after a typical conversion.

1 Xebra Hatchback at 84v