Newhouse Farm

pyrogaz · Posted: Sun Sep 27, 2009 8:53 pm Post subject: Electric car racing for schools

I couldn't find any previous posts about this so thought I'd bring it to everyone's attention. This website http://www.greenpower.co.uk/about/ is all about Greenpower which is an organisation that runs an electric car endurance race series for schools, colleges and young people in other forms of educuation/training

I help the teams at our local high school and both of my kids are heavily involved, I'm sure there'll be a few other folk on here who do likewise. There are rules and regulations designed to keep the costs and speeds down but even so the performance in terms of distance covered is quite remarkable, using just two pairs of 70Ah 12v lead acid batteries which cannot be recharged during the race it's now commonplace to exceed 100 miles in 4 hours with the current record being 144miles! That's about 0.3p of electricity per mile or equivalent to 1900mpg for a petrol car.

The motors and batteries provide very little power so the whole design, construction (often using lots of recycled parts) and development process really gets the students thinking about efficiency and how to apply their engineering knowledge to solve problems. It's just a pity the cars don't comply with UK law for use on the public road, many of them would be ideal for commuting 10 or 20 miles to work and back!
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"Scotland has two seasons, June and Winter". Billy Connelly.

EVguru · Posted: Tue Sep 29, 2009 11:14 am Post subject:

Oh, Greenpower has been mentioned here before.

I along with other menbers of the Battery Vehicle Society demonstrated some of our vehicles at a greenpower event at Goodwood a while back. My electric motorcycle let me down when the salvaged auxillary battery failed on the first lap, but another BVS member produced a replacement from the back of his Citroen Berlingo EV on the second lap and I didn't have the embarassment of the recovery truck.

I think Greenpower is a great idea, it's very similar to the 'Electrathon' events the BVS organised back the in 70's. My only real criticism is the non sustainablity of the motors. They're really worked too hard and I believe many teams replace the motor each season.
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Paul
www.evguru.co.uk
www.batteryvehiclesociety.org.uk
www.compton.vispa.com/the_named

pyrogaz · Posted: Tue Sep 29, 2009 3:04 pm Post subject:

In some ways the relatively low efficiency of the motor is a problem as it makes it easy to damage it through overheating which is why some teams have to replace them, on the other hand it stops the kids going nuts with a highly efficient brushless motor that could get them up to 60mph (albeit at the expense of the batteries!) in cars that aren't designed to go that fast.
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"Scotland has two seasons, June and Winter". Billy Connelly.

EVguru · Posted: Tue Sep 29, 2009 3:35 pm Post subject:

I have no problem with a low cost 'spec' motor, but it's totally enclosed and therefore very difficult to cool.

The motors are 'sealed' to prevent 'blueprinting' or rewinding of the armature, but you can drill the endplates for ventilation as long as you don't dismantle the motor to do so. Doing so without damaging the windings probably takes as much luck as skill. I think they should just supply a special version of the motor with drilled endplates.
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Paul
www.evguru.co.uk
www.batteryvehiclesociety.org.uk
www.compton.vispa.com/the_named

pyrogaz · Posted: Tue Sep 29, 2009 8:51 pm Post subject:

Drilled motors were banned this year, teams who had already drilled their motor could continue to use it until next year. We find that even if the unmodified motor is mounted away from any airflow as long as we don't exceed 25A the motor stays below 35c, if you use more than 25A for any significant period of time you'll run out of batteries before the end of the race anyway.
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"Scotland has two seasons, June and Winter". Billy Connelly.