Roper ZAP PK Xero (Sun Roper) Existence Log

L. David Roper
http://www.roperld.com/personal/roperldavid.htm

http://www.roperld.com/science/ZAPXebraPKRoper.htm

Books about cars, especially electric

Mileage Record

Modifications Made

Problems Fixed

Suggested changes for future ZAP Xebra PKs
ZAP Xebra PK review

Unless stated otherwise all miles driven are actual miles, which are obtained by multiplying the Sun-Roper odometer miles by 0.86 according to a ZAP technician and my Garmin GPS.

Monthly log records of Sun Roper:

1. March 2007 (arrival, insurance & registration)
2. April 2007 (Sun Roper decal, solar panel, newspaper article, Gottlieb front spring, PK parameters, voltage graphs, PowerCheqs installed, brake changes, bed liner inside, runaway Sun Roper, rear-view mirror, Virginia motorcycle drivers license)
3. May 2007 (tailgate chains, drag coefficient, PakTrakr, wiper quit, glove-box expansion)
4. June 2007 (PakTrakr current sensor, Woodward rear springs, side markers, home-made motor shield, O USE Helmet acronym, YMCA charging station)
5. July 2007 (4th-July parade, winch plans, install solar panel)
6. August 2007 (Steppin' Out, solar-panel ammeter, replacement axle)
7. September 2007 (wheel drag, reverse problem & desulfator install)
8. October 2007 (Woodward motor shield, hauling Sun Roper, emergency-brakes spring, River Roper kayak on Sun Roper)
9. November 2007 (Sun Roper @ Energy Expo, driveway plug, battery tester, door liner)
10. December 2007 (charger algorithm 42)
11. 2008 (bad batteries, blown charger fuse, Woodward large display, new battery set, 84-volts conversion, Guest charger, broken emergency-brake cable, charger-fuse-holder bad, Woodward display with SD card, new radio, bad DC-DC converter, replaced PowerCheqs with BattEq, simple EV circuit, bad charger)
12. 2009 (lithium batteries, 1C discharge curves, 95V charger/balancer, LiFePO4 batteries layout, PakTrakr for LiFePO4 batteries, auxiliary battery replaced, interlock bad, BattEq return for refund, antenna replaced, LiFePO4 batteries installed, bad LiFePO4 battery, batteries type comparison )
13. 2010 (lithium batteries)

(Some of the problems mentioned in these daily logs have been fixed in later models.)

Analysis of logged Sun Roper trips.

Mileage Record for First Two Months (April & May 2007) of Driving

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The asymptote is 2.83 miles/kWh. This could be thought of as batteries conditioning and driver conditioning combined.

The asymptote is 3.62 miles/kWh. This should be reasonably independent of driver conditioning. Of course, it does depend on how the driver drives; I tend to drive full throttle, but I do coast at 40-45 mph down hills and up to stop lights and signs as much as possible. Note that all three fits are very similar. It appears that the miles/kWh would improve if I drove more miles per day; that is, the motor would "like" to have more energetic batteries. Some of the days had opportunity charging.

Data and quadratic fits to data for miles/day <= 10, 10 < miles/day < 20 and miles/day >= 20.

Range versus driving day calculated at 9.75 kWh useful battery storage.

Monthly miles/kWh versus months driven. The solar panel was in operation for the last week of month 4 (July 2007).

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Things I would like to have changed on the PK:

• Left mirror flat instead of convex.
• Center mirror with night lever attached to the windshield instead of to the roof light.
• Windows roll all the way down below the sill.
• Door of charging plug open upward to form a rain deflector, instead of frontward.
• Bigger glove box that extends below the lip.
• Storage pockets in the lower portions of the doors, on the front-wheel well and on the walls behind the two seats.
• Glove box that extends downward below the box sill to keep items from falling out.
• Window handles that point upward and to the front when windows are fully open and fully closed.
• 20" or longer wiper blade.
• 2" longer prop for the hood.
• kW meter & kWh readout in dash.
• Paint under the bed sides hinges and tailgate hinges.
• Undercoat the bed and frame.
• Electric system operates when foot brake is depressed, but not when emergency brake is on.
• LED lights as much as possible.
• LED side markers instead of reflectors.
• Adjustable softer springs/shocks on all three wheels.
• Electric lift option for the bed.
• Wire the contactors to fix the contactors problem.
• More rigorous quality control.
• Battery equalizers as standard feature or an option.
• Include a paint touch-up kit.
• Make cab a foot wider so that the brake and accelerator pedals are in a more normal position.
• Make cab a foot deeper so that there is more variability in seat position and seat-back angle.
• Repair manual telling how to take the vehicle completely apart in proper sequence.

Books about cars, especially electric

• The Electric Car: Development and Future of Battery, Hybrid and Fuel-Cell Cars by Michael H. Westbrook, 2005.
• The Electric Vehicle and the Burden of History by David A. Kirsch, 2000.
• Taking Charge: The Electric Automobile in America by Michael Brian Schiffer, 1999.
• Electric and Hybrid Vehicles: Design Fundamentals by Iqbal Husain, 2003.
• The Essential Hybrid Car Handbook: A Buyers Guide, Nick Yost, 2006.
• Plug-in Hybrids by Sherry Boschert, 2006.
• Forward Drive: The Race to Build “Clean” Cars for the Future by Jim Motavalli, 2001.
• The Hype about Hydrogen by Joseph J. Romm, 2005.
• Lives Per Gallon: The True Cost of Our Oil Addiction by Terry Tamminen, 2006.
• Internal Combustion: How Corporations and Governments Addicted the World to Oil and Derailed the Alternatives by Edwin Black, 2006.
• Traffic Safety and the Driver by Leonard Evans, 1991
• High and Mighty: SUVs: The World's Most Dangerous Vehicles and How They Got That Way by Keith Bradsher, 2004.
• Electric Dreams: One Unlikely Team of Kids and the Race to Build the Car of the Future by Caroline Kettlewell, 2004.
• Carfree Cities by J. H. Crawford, 2002.

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