John Brett

John is a professional engineer with 50 years experience.

John has designed and built many cars, trucks, and vehicle assembly facilities.

John has worked on design of roads, bridges, cranes, transmission towers, and buildings, and operation, maintenance and upgrade of hydro and gas turbine power stations.

John was a LVV Certifier for 13 years. John has long been a whistle-blower, expressing the view that the LVV system is dangerously deficient. John’s authority was revoked in December 2012.

John rides a 1992 Yamaha FJ1200ABS, and is also a keen road and off road cyclist.


“The LVVTA has brought it to my attention that statements I have made in relation to it and its employees may have been perceived as defamatory.

I sincerely regret that and apologise for any harm caused. I have taken down the statements identified by the LVVTA of concern to it.

I have strong views about the low volume vehicle certification process and intend in the future to direct my energies into the public inquiry now being held in relation to it.”

John Brett 7th October 2015


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Electric Rav 4

We have Certified a number of Electric Vehicles.

RAV4 EV under construction

RAV4 EV under construction

The vehicle shown runs on an AC motor, with lithium Ion batteries. Other vehicles run on DC motors and lead Acid Batteries.

When Lead Acid batteries are used, ventilation is required to ensure that the hydrogen gas given off cannot be ignited, or fill the inside of the car. Lithium Ion batteries do not have this problem.

Weight is a major consideration, the LVVTA advise that the GVM of the vehicle cannot be exceeded, which can limit the number of batteries used, or require seating positions to be removed. A good vehicle to convert is a commercial vehicle which will have a much higher GVM for load carrying, ths will allow a greater weight of batteries to be carried.

Vacuum brakes pose a challenge- one solution is to fit an electric vacuum pump.

Power Steering is another challenge- there are electric steering systems in some vehicles, and there are electric power steering pumps also.

Good news is that Electric Vehicles are exempted from Road User charges, which makes a huge saving in runing costs, (along with the saving in fuel of course)

To ensure that you avoid any LVV Certification problems, talk to John at an early stage

This is a very interesting website- Earthlings Electric Vehicles


This vehicle was also used last year by the Low Volume Vehicle Technical Association for Certifier training for Electric Vehicle Certifiers

Unfortunately I wasn’t invited because they don’t want me to Certify Electric Vehicles- even though I Certified the car they used as an example for training! Go figure!

John Brett Technology Ltd. 0800 LOW VOLUME (0800 569865)

18 comments to Electric Rav 4

  • Andrew Merton

    I am converting a 1995 BMW (328i) to be electric. Its GVW (Gross Vehicle Weight) from the handbook (and the plaque attached in the engine bay) is 1780 kgs.

    How much I can increase the weight? I have removed around 307 kgs (engine, exhaust, radiator, petrol tank etc), but would like to use 12 batteries that weigh 37kg each (444kg total), along with a 73 kg motor and around 20-30 kg of other equipment. So there is s net gain of ~235 kg.

    The car has 2 front seats, and the rear seat is 1250mm, which I believe means it’s a 5-seater.

    If I fix the center rear armrest in the lowered position to reduce the number of seats to 4, I believe I save 80 kgs as far as the LTSA is concerned 🙂 This would make the total weight (1780-307-80+444+73+30) = 1940 kg.

    Is this an acceptable increase over the GVW (about 9%)?

  • johnbrett

    Hi Andrew-

    Your figures:
    Car manufacturers do not normally publish Gross Vehicle Mass for passenger cars.
    Since your car has that information, this is what we would use.

    The usual procedure we use to design Electric Vehicles is:
    1 Determine kerb weight, in unmodified state.
    2 Add the fuel load, passenger loads to give a calculated GVM (note that Landata often shows GVM for cars, if so, then that figure is the starting point)
    3 Subtract passenger weights and fuel weights to give maximum allowable Kerb Weight for MODIFIED vehicle.

    If you estimate the weight of the original engine and fuel tank being removed, this is the maximum weight your new motor, control system and batteries can weigh (which is what you have done).

    Passenger cars do not have much margin, light commercials are MUCH better and they always have published GVM figures.

    One possibility is to remove the rear seat altogether, to give you ( 3 x 80 =240kg) extra battery capacity.
    If you reduce the seating positions to 4, you need to fit some PERMANENT armrest or such to stop that seat being used. We have had this issue on Limousines, and LVVTA are quite inflexible about this. I have had Certifications turned down because an armrest fixed down was not deemed permanent enough!

    Re the suspension- if you increase the mass you MAY need to up-rate the springs to keep the suspension operating correctly. There is no mandatory ride height, the LVVTA Standard is performance based- i.e. the suspension still has to work properly.

    Hope this helps



  • You post great articles. Bookmarked !

  • Hi there can I reference some of the material here in this post if I link back to you?

  • John Brett

    GVM Increase- I am advised by LVVTA that the GVM may NOT be increased over the standard rating. Check what it is on LANDATA (either through Motochek, Car Jam or have a WOF agent look it up directly on Landata.You will be surprised to see that there is usually no allowance for luggage- for example a five seater car will have allowance for 5 passengers at 80 kg, but NO luggage, NO towbar downforce!

  • Ryan Callanan

    Hi John. I am 90% through a PHEV hybrid conversion to my toyota estima van. I am adding a 10kw series dc, 72v to it but not removing any of the existing parts (motor, trans etc). It can still run as normal on petrol, on electric or both (with the electric assisting the petrol) Just wondering what will be required to get it certified for the road. I know the lead acid batteries need to be boxed and vented. I sthere anything else. Where would I take it to get this type of conversion certified.



    • johnbrett

      Hi Ryan
      You will need to have it LVV Certified- the biggest issue I see is keeping the Gross Vehicle mass the same. If you add batteries, you will probably have to remove some seats. Re battery venting- if you could mount the batteries beneath the vehicle the venting issue is solved- would that be a possibility on an Estima?
      Best wishes John

  • johnbrett

    You would need have this LVV Certified, give us a call on 0800 LOWVOLUME (0800 569865)
    The biggest issue will be the GVM, you will need to remove some seats.
    Venting of batteries- is there not room underneath an Estima to hang batery racks?

  • John Spence

    Hi John
    Above you stated the following.:

    The usual procedure we use to design Electric Vehicles is:
    1 Determine kerb weight, in unmodified state.
    2 Add the fuel load, passenger loads to give a calculated GVM (note that Landata often shows GVM for cars, if so, then that figure is the starting point)
    3 Subtract passenger weights and fuel weights to give maximum allowable Kerb Weight for MODIFIED vehicle.

    My question is in step 3, why would you subtract the fuel weight? The full fuel weight would normally be carried by the vehicle. Yet on an electric vehicle, electricity(fuel)weighs nothing. Surely you could include the weight of the fuel as additional weight for the conversion process. Can you please explain the background behind this.

    John Spence

    • johnbrett

      Hi John
      Hey- you are right! there is no need to subtract the fuel weight.
      The bad news is that the LVVTA seems to have promoted themselves to ‘Over-Certifiers” who make all decisions. The nominal LVV Certifier just feeds the LVVTA with the information, then signs off on their (frequently wrong) decisions.
      I am one of a number of LVV Certifiers in the middle of a big arguements with LVVTA and NZTA about LVVTA’s delusions of grandeur, we find it an unacceptable certification process.
      You could contact Dan Myers at LVVTA, however you may have difficulty finding an LVV Certifier to actually do the job at present.


  • John W

    Nice site. Am I allowed to put a J1772 socket in my car and connect with the right interface to a onboard charger? Since it will not be directly plugged into the mains because a J1772 charging system requires a special device plugged in between the mains and the car with intelligence that wont feed power until the car end communicates the plug is locked in all ok. Does this mean my car WONT need to be checked over by an electrician? And will my onboard charger have to have the AU/NZ tick off approval in this case or no?
    The guidelines say you cant have a female socket yet all the factory cars have J1772 sockets… It would be unfair if conversions cant use this tidy system.

    • johnbrett

      Hi John
      In reply- The J1772 socket is the one to use- I’m not sure if the Electrical Wiring Regs have caught up yet. The ‘No Female socket’ rule applies to e.g. appliances, extension cords, caravan leads etc, however the J1772 has been designed to be used this way. I would in any case get a good Electrician involved at an early stage- you might have to ask around to find someone experienced in the area. There are lots of potential traps with Electricity, even if you don’t actually fall into any, you would want a sign off from a sparky for your legal protection.

      BTW- I have an “Electric Car Challenge” for you. Show me the Electric car that can travel the course of the Lake Taupo Cycle Challenge on one charge. I can do it on my Pinarello in about 7 1/4 hours, and I’m 70.

      Hope this helps


  • John

    Hi John

    I wasnt expecting your fast reply. Thank you. I think only a Tesla model S could do that range. Im not a ev egghead/ecohead etc. :). Im more interested in the technical side and being able to make something new from something old. All going well being able to drive to work and back would be nice. Im glad I can probably use that plug. The interface has been adapted to conversions and is inherently quite safe as no power flows until the car talks to the external charger and says all ok plug firmly clicked in etc. Your cycling fortitude is impressive and a great example.


  • Mark Waters

    Hi John, I’ve converted an XS1100 Yamaha to electric using a forklift pump motor an 3 deep cycle gel 12v batteries, I need some advice on getting it certified,any help would be much appreciated.


    • johnbrett

      Hi Mark
      What an interesting choice of bike! I guess that the shaft drive was relatively easy to connect to an electric motor. What wattage is the pump motor? Is it still going to be superbike? (I’ve got a nice FJ1200 1992 model, and it’s an astounding bike to ride. Certification- I don’t know ANY Certifiers who can do this- I would start by talking to Alex Gee on 027 264 7282, or email He does most of the motorbikes, but not sure he is allowed to do the electrical part.


  • Kevin j CLANCY

    Hi I am planning on converting my 1986 Honda City to EV – My goal is to end up with a car that weighs the same as it did before I started the conversion – If I go 10 or 20 KG over will I fail ? Should I get the car professional weighed before I start the work?

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