1990 Mazda Miata Electric Car
Individual battery voltage is displayed on the left digital meter and is selected with the 13 position rotary switch. The right hand digital meter is the bus voltage. The analog meter is 200 amps FS and is the system current. The little toggle switch reverses the meter to indicate charging current.
February 2005. The batteries were replaced with 125 AH flooded cell units.
January 2005. The car was finally painted. Looks nice!
May 2004. The battery monitoring panel was finally installed.
April 6, 2003. Thirteen new Optima Blue Top deep cycle batteries installed and operational. Top speed is 96MPH. The range is at this speed is only about 10 miles.
March 2003. The GNB batteries are dying like flies, but they managed to give me 2,000 miles of fun driving. They were not designed for deep cycle service and did quite well considering the demands put on them. They were also free. I am now installing Optima D31M 75AH Blue Top Marine deep cycle batteries and expect to be done by April 7. I will be using 13 of these compared to 11 of the 90AH GNB's and will be using the same 20 amp on board charger. I will loose about 120 lbs in the rear and pick up about 20 lbs in the front.
June 8, 2002. The 1990 Electric Miata had its first trial run. All systems working. Top speed is about 85 and it accelerates just fine in 5th gear. Total weight is 2860 Lbs., 1440 on the front and 1420 on the rear.
Things left to do are:
Install new top, install stiffer springs to raise the body back where it belongs, refine the charging system and
paint it.
Bill enjoying the summer of 1940
- Bills first car project in 1955 at age 15. The engine is a 5 HP Tecumseh which is just visible along Bill's right side and over his right shoulder. The 10:1 belt reduction pulley is just visible behind Bills left hand. No clutch, brakes, drive train safety covers, safety belts, helmets, OSHA, EPA or strict enforcement of the laws. The cops looked the other way. Boy did we have fun! Note the foot accelerator and the spare wheel being used as a steering wheel. The car is made entirely out of 2 X 4's.
- Bill (on the right) in his garage with neighborhood friends during the building of the go-cart. July 1955.
- Now, 47 years later (2002), the 1990 Miata Electric Car Conversion. The conversion uses 11 GNB 90 amp hour VRLA batteries and an Advanced FB-4001A motor rated at about 20 horsepower. Peak horsepower for short spurts is about 85. Four batteries are installed where the spare tire used to be. Two more are behind the front seats where the gas tank was, and 5 more are up front in the motor compartment. This is an on going project so check in from time to time to see the progress.....
- The electric motor is mounted to the transmission with a 1/2" thick home made adapter plate and a 1.25" thick spacer ring. A Motor / flywheel adapter hub connects the 1- 1/8" motor output shaft to the flywheel. The left end of that long aluminum support structure bolts on to the differential. Note the shift lever in the center.
- The motor with the 1.25" thick spacer ring installed.
- This shows the 1.25" spacer ring and 1/2" adapter plate bolted onto the drive end of the motor. The Motor / flywheel adapter hub is keyed and set screwed onto the 1-1/8" drive shaft.
- Motor / flywheel adapter hub installed on the flywheel with 1/2" by 2" cap screws.
- These are the old GNB batteries that were located in the trunk where the spare tire used to be. The tops are about 2" below the trunk deck line which is covered with a piece of 1/2 inch plywood. The bottom of the battery tray is even with the bottom of the bumper. The black box is the meter current shunt.
- Two more batteries are located behind the front seat in the space where the gas tank used to be.
- Three of the five front batteries. Note the heavy RTV insulation on the battery terminals. All exposed wiring will be insulated like this.
- The last two batteries installed up front with the motor.
- The PWM motor controller mounted on its heat sync. It's a Curtis model 1231C-8601 rated at 500 amps, 144 VDC. That's 72KW, just shy of 100 HP.
- The charging system consists of four Lambda power supplies connected with the 240 vac primaries in parallel and the secondarys in series. Each supply is set for 45 vdc, and the four outputs in series gives 180 vdc at 20 amps. This is about 13.85 volts per battery. The dimensions of these supplies are 5 X 5 X 9, internal fan cooling, and are rated for 1071 watts each. They were donated to the project through the generosity of Hendry Telephone Products, Jim Keenan President. Thanks Jim!
- Sometimes Bill really gets into his work!