Comments on: Electric Rav 4

By: Erin Turner

Erin Turner — Wed, 11 Aug 2010 05:48:17 +0000

AC motors are more efficient than DC motors and requires less maintennance ~

By: John Brett

John Brett — Fri, 30 Jul 2010 21:52:53 +0000

GVM Increase- I am advised by LVVTA that the GVM may NOT be increased over the standard rating. The previous comments about 10% increase is now not applicable. To find the GVM for your vehicle, 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!

By: Quentin Camacho

Quentin Camacho — Thu, 17 Jun 2010 18:14:54 +0000

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

By: zaklady bukmacherskie

zaklady bukmacherskie — Fri, 28 May 2010 12:30:31 +0000

You post great articles. Bookmarked !

By: johnbrett

johnbrett — Tue, 27 Apr 2010 20:33:05 +0000

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 Add 10% to this
4 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, then add 10% of GVM (say about 200kg), 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.
The 10% is not a formal rule as such, we could try for a little more, if we could give justification for it- (i.e. show evidence that these axles could be expected to handle this higher loading)

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

Regards

John

By: Andrew Merton

Andrew Merton — Tue, 27 Apr 2010 09:34:54 +0000

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%)?