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EV Specifications

This page provides a quick summary of the technical specifications of my Toyota MR2 EV.

Performance

  • Range: 50 miles. Conditions: 55mph, mostly level, 60 degrees ambient, dry, neutral wind. Will still do 30 miles safely in rain, wind, cold, hills, etc.
  • Top Speed: 70mph reached pretty easily. Conditions: level. Would probably get to 75 if I pushed it.
  • Hill climb angle It will start from a dead stop on a ~15% hill in second gear, so it can probably start from a dead stop on a ~20% or worse hill in 1st. The steepest hill in my area is a 18% grade.
  • Acceleration I haven't tried to measure 0-60 yet but it will be around 20 seconds. Conditions: Level, all in 3rd gear.

Note: May 10th, 2008: Maximum range achieved. I participated in an EV range rally organized by members of SEVA (Seattle Electric Vehicle Association) and went 66 miles of distance on one charge. This included 56 miles of freeway driving on Interstate 5 in south Everett. Ambient temperature was 55 degrees farenheit, and conditions were dry but with a 10mph southernly wind. My route included one round trip from exit 186 to 199 and back, and three round trips from exit 186 to 181 and back, and several small surface street loops. This performance was good enough for 2nd place overall in the rally. The winning car, a very heavily modified geo metro with 1700lbs of batteries heated to 120 degrees, did 101 miles on a similar freeway route.

Conversion Effort

  • conversion time: about 750hrs over a 9 month span: january through august, 2007
  • Conversion Cost: $11500 total EV Project Expenses, including car, EV parts, batteries, chassis repairs, everything to get it running. Range and Performance Upgrade (adding 4 more batteries): about $400 (new batteries acquired at 1/2 retail price)
  • Work Space: 800sf basement workshop and a covered carport.
  • Major tools: Shop Crane, Hydraulic Jack, Jackstands, TIG/Stick welder, Sawzall, Electric Drill, Cutoff wheel, Dremel tool, Angle Grinder, Propane torch, Heat Gun, Full set of Sockets/Wrenches (Metric and Inch based) and many other hand tools, C-clamps, spring clamps, Measuring equipment, Hammer Crimper, Cable Cutter

Chassis

  • Make/Model: 1985 Toyota MR2. Mid engine, RWD sports car.
  • Curb Weight: 3400 lbs. (was 3140lbs prior to Range and Performance Upgrade)
  • Original Mileage: 189335
  • Suspension: Upgraded Springs and Shock Absorbers. See EV Suspension System page.
  • Brakes: Vacuum assisted 4-wheel disc. Upgraded rotors and pads. See EV Braking System page.

Drivetrain

  • Transmission: Original, modified for efficiency. See EV Transmission Modification page for details.
  • Motor: Advanced DC 9 inch with tailshaft. See Motor and Adapter Plate page.
  • Mounting Points: Motor mounts redesigned to reposition entire drivetrain assembly to allow battery installation
  • Tires: Bridgestone B381 low rolling resistance.

EV Electronics

  • Controller: Curtis 1231C 500A, 144v rated. See EV Electronic Components Overview for details.
  • DC-DC Converter: Sevcon 25A 13.5vdc output, 60-100vdc (80vdc nominal) input.
  • Gauges: 500A ammeter, 80-180v voltmeter
  • Vacuum Pump: SSBC (Stainless Steel Brakes Corporation) Vaccum brake pump kit. See EV Braking System for details.
  • Charger: Russco 24-120 with boost transformer. See EV Charging System page.
  • Main Contactor: Tyco Electronics 250A continuous
  • Reversing Contactor: Albright
  • Fuses: Three, 500A each distributed across battery pack
  • Circuit Breaker: Heinemann 250ADC continuous. Accessible to both driver and passenger.
  • Cabling: 55 feet of red 2/0 welding cable used.

Traction Battery

Curent Battery (See EV Traction Battery page):

  • Technology: Flooded Lead Acid.
  • Battery Model: Trojan T-105 with UT type terminals.
  • Battery Count: 21
  • Pack Voltage: 126v
  • Nominal Capacity (kWH): 28
  • Practical Capacity (kWH, estimate): 16
  • Layout: Ten in engine compartment, seven in front compartment. Four in sunken compartment of trunk, preserving most of the trunk space for cargo.

Original Configuration: (See my Range and Performance Upgrade page for details on why I didn't stay with this configuration)

  • Technology: Flooded Lead Acid.
  • Battery Model: Trojan T-105 with UT type terminals.
  • Battery Count: 17
  • Pack Voltage: 102v
  • Nominal Capacity (kWH): 23
  • Practical Capacity (kWH, estimate): 14
  • Layout: Ten in engine compartment, seven in front compartment. Zero in trunk.