For registration in NSW Australia every electric vehicle conversion needs a 12 Volt battery to power the ancillaries, primarily the hazard lights. But it is also pretty convenient for powering pre-charge circuitry and contactors when starting the car. In MR02EV I recently upgraded to a Drypower 12V 22Ah sealed lead-acid battery.
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When I bought the 1989 Toyota MR2 that was to become MR02EV, it was pretty un-loved. Especially the wheels which had been painted with white house paint. I could have refurbished them, but I never did like the originals so started looking for alternatives, which started a minor obsession with wheels and conflict with my Wife (cars can do that)! Motor controllers for electric vehicles like the TIM600 in MR02EV typically have a large internal capacitor bank on their input with very low Equivalent Series Resistance(ESR). As such they require inrush protection when first powering up to prevent a large current spike which can damage components – most commonly, welding contactors shut or blowing fuses. In MR02EV I use a ZEVA Smart Precharger which is designed with a 2-stage soft start to limit inrush current via a resistive circuit that charges up the inverters internal capacitors before automatically closing the main contactor when the process is complete. www.zeava.com.au
I have been driving MR02EV for about 4 years using a battery pack consisting of 56 Thundersky lithium-ion cells totalling 201.6 Volts and 12kWwh; it has served me pretty well. Initially my driving was in city traffic 0 – 60 kph so performance was not an issue and the 70 kilometre range was more than adequate. Because Electric Vehicles do not have an internal combustion engine there is no traditional vacuum source to supply the brake booster, so a vacuum pump and vacuum flask is needed. In fact it is mandatory for registration of the vehicle.
The modified Corolla gearbox which is now a 2 speed was finally installed into MR02EV (see earlier posts for details on the modifications).
(Making a Two Speed Gearbox From a Five Speed Gearbox)
MR02EV has been a registered road going vehicle for 3 years and covered about 12,000 kilometers in that time, mostly through commuting to work and running around town. It’s a fun car to drive. But right from day one the gearbox has been plagued with problems, excessive noise and excessive backlash, which has just gotten worse over time.
In April 2013 an Automotive Engineer certified MR02EV as road legal, I obtained a vehicle safety compliance certificate (an engineering certificate) and was able to legally register the car in NSW Australia. Following is an extract from the engineer’s report which gives you a flavor of the information required.
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Michael Day
I have a Degree in Electrical Engineering from the University of Technology Sydney and am employed in Broadcast Television Industry. My hobby is the (continuing) modification of MR02EV. I am also the National Treasurer of the Australian Electric Vehicle Association. Archives
October 2018
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