evnz
electric vehicles new zealand
The Toyota Vitz was bought in June 2008. I wanted a small but safe car for city driving but a new enough car that would be my only car and last ten years. It has dual airbags and the best safety record according to the Dog and Lemon Guide (which is by the way extremely dismissive of electric cars.) I had not worked on a car since 1980 and before then had taken several Morris 1000s apart. I found my socket set from 1973 and started on the conversion. 18 months later and $NZ15,000 poorer I am driving 16 to 20 Km a day to work and back in a fully legally certified , Warrant of Fitnessed and insured car. Its range is a little disappointing and acceleration mediocre but it mainly keeps up with other cars in the traffic-clogged streets of Auckland NZ. It comfortably reaches 100Km/Hr on motorways. I am planning to add 24 volts of Lithium batteries to bring the total DC voltage up from 96 to 120 which will better match the slightly too big motor, but that is another $1800. I am trying to resist further tinkering with the car and concentrating on incorporating the electric car into my life so becomes just a normal element of my daily transport options. Note: The batteries went flat and the car was off the road for 6 months while i re-evaluated what to do. I now have the car running again on new batteries |
Buying the car
The kerb weight was 830kg and the fully laden weight allowed 1320kg meaning the weight of people and batteries able to be carried was 490kg. I bought a 3 door rather than a 5 door by accident but now that there are only 2 seats it doesnt matter.
Ordering the kit
After many enquiries and following the guidance of Gavin Shoebridge from New Plymouth whose website tells an amazing story of his conversion I chose to import a kit from EVAmerica because he had found them so helpful. I think it cost me $7,000 to import the motor, controller, DC-DC converter, cabling, charger, fuses, shunt and gauges and lots of other bits. This includes GST and some duty. This was with the NZ dollar at US73c
How many volts
Because I chose to use lead acid batteries my original conversion with 4 seats could only have 96 volts of 105AHr batteries at 22 Kg each X8 giving 176Kg total battery weight. The controller is rated from 72V to 120V so I would be able to vary the battery pack if I wanted. The motor can take 72-144 volts so that is flexible too. The current car at 72 volts is seriously under powered especially as regards top speed.
Removing the ICE
This was scary as car engines had changed since the 70s especially with computerisation. I started out recording wherre everything came from but soon realised my conversion was going to be irreversible by me.
Coupler and adapter plate
I had these frabricated for me and this was an area where I was seriously inexperienced These 2 items cost over $2000 which was a shock. I used the dimensions and specs from a conversion in Australia of the same car.If I was doing the conversion again I would go for 2x 48 volt motors each coupled to a front wheel using the left side (shorter driveshaft) This would eliminate the gearbox and save enough weight to add 3 more batteries bringing the pack voltage up to 96 volts
Batteries and boxes
These were welded out of angle steel by my local engineering firm who were very helpful. The front battery holder in particular was quite complicated, slung between the chassis rails in front of the motor. the rear one fitted in the tyre well with 4 batteries. There was one under the back seat and 3 at the front making 8. In the mark 2 conversion There were 4 in the tyrewell, 3 under the back seat and 2 at the front giving less weight on the front wheels and therefore, importantly, easier steering without using power steering which now I hardly ever use
Constructing the board
I followed the video and diagrams which came with the kit which ws based on a larger car, so space under the bonnet on the little Vitz was severely constrained. The cabling and contactors laid out on a piece of plywood are quite exposed rather than hidden away in a box. This means someone could easily electrocute themselves by poking around under the bonnet. When you open the bonnet there is a large red warning sign which always causes mirth at the vehicle testing station. There are two well marked Anderson disconnectors which renders the whole board dead when they are disconnected
Vacuum brakes
Because the engine is not running continuously therre is nothing to generate vacuum to assist the brakes .This is overcome by a 12 volt vacuum pump and switch which automatically activates the pump when the vacuum falls below 15 and turns it off when it reaches 23. This means when the ignition key is on there is always enough vacuum for the brakes. Should the 12 volt system fail there is enough vacuum in the system to stop the car. I also have a vacuum pressure gauge on the dashboard to reassure me that all is well. I could have a warning buzzer to indicate failure but so far I always drive with the stereo on so if it suddenly stops I know I need to brake and stop
Power steering
This was a real poser. Eventually I bought a 12v winch, removed the planetary gears and mounted the motor with a pulley wheel glued on the shaft with araldite. This drives the power steering via a belt. The motor is barely powerful enough so I can switch it on and off with a dashboard mounted toggle switch. In fact I only use it when parking in a tight space.
High voltage system
12 volt system
The 12 volt system which controls the electic motor, vacuum pump and power steering is an independent addon to the whole of the existing 12 volt system. This means lights, fans, horn, stereo, indicators all operate as in the original car
Charging
This was one of the biggest problems. The charger I ordered was not available in 230 volts so I was given a Quickcharge brand which was very heavy (12kg, adding to vehicle weight) and drained my household wiring on startup, often throwing the curcuitbreaker on my switchboard. I now have three Meanwell 24 volt 15 amp chargers which are tremendous, recharging the pack in 2-4 hours and weighing only a couple of kilos each. As well they draw a max of 1800 watts but they cost $1300. They are connected to a 4way board behind the passenger seat and the plug lies on the floor beside the handbrake. I bring an extension cord from my garage power point through the drivers window and the connected plugs drape over the steering wheel. This means you can not drive off with the car still connected and also the window can be wound up with the cord running through the top and the car is secure while charging and the cord can not be removed unless you have the key to unlock the drivers door. There is additional protection against driving off while charging with a relay curcuit not allowing the 12 volt control curcuit to be activated while the batterybox fan is running, This fan runs automatically during the charging process to void explosive gasses released during charging from the rear enclosed battery box. It also runs on a timer for a further 4 minutes after the charger is turned off.
Safety systems
There are many required safety systems especially involving the very high current the batteries are able to generate. remember 72 voltsx 200 amps equals 14000 watts, a lethal hit. There is a fast acting fuse between battery 4 and 5. All the high voltage cables are inside orange conduit tubing. There is also a physical disconnect between battery 4 and 5 operated by an orange lever beside the hand brake. Should the car hit something and stop suddenly an inertia switch cuts out the 12 volt system, which opens the 2 connectors thus isolating the controller and motor. The system can also be turned off with a red panic button below the cigarette lighter
Getting legal
Driving around
