Battery Vehicle Society

I said I'd keep you abreast of my experience with my EV trike. I've covered 527 miles so far.

My trikes information is best accwssed on "EV albums" where it is described as a Kirk EV or "Sparky".

Briefly it is a 2F1R trike with a Mars ME0709 motor, Alltrax 7234 controller and 6 Elecsol 12V 110Ah batteries.

The Wh/mile figure is considerably higher than I had anticipated, with an obvious effect on range. Driving carefully I can get 115Wh/mile but this is tedious. Driving more spiritedly I acheive 130-150 Wh/mile. This means that after less than 20 miles the controller is intervening due to voltage sag to <60V. The most I have acheived is 26.16 miles where the lowest voltage I saw was 63V. The best way to drive it is to only do about 10 miles. Then it's quite nippy and you are not going to see <67V.

One thing that has suprised me is that it climbs hills better than calculations would have suggested. I can stop on a 10% gradient and accelerate to 24mph before it's had enough with the controller set to a max. output of only 180A. With a 405Kg weight including my self this should not be possible! I should only reach 14mph-good news then.

I am currently using my chargers profile and 14A capacity to calculate the Wh/mile figures, so there may be some error butapart from the range being less than I'd hoped (due to the electron consumption being higher than my best estimate) all is going well.

It's just a shame that I never need to drive 10 miles but need to do 25 miles 12 times a week!

I suppose I could alway spend thousands on Li ion for them to mysteriously catch fire whilst charging one day, or get some expensive Trojans which will give me 200 journeys to work for £1200. (Though with their weight I wouldn't actually make it)

Electric vehicles have there limitations, as some Nissan owners will find next year when 100 miles range turns out to be 45 miles of normal driving....................BUT DON'T YOU JUST LOVE THEM!!!!!!!!!!!!!!!!

Andrew.

Nice review Andrew

What average discharge currents are you seeing.

ChrisB

I know this is not great but I don't have an ammeter! I know when I am using more amps merely from the voltage sag. I built the vehicle in a minimalistic way. I have monitored the motor temperature to make sure I am not over stressing it. I have also checked the controller temp. and all is well. I have checked individual battery voltage under load. At a high state of charge they are almost identical. At a high state of discharge they start to vary much more.

This has convinced me that for battery life I will have to restrict my journeys to less than 20 miles.

To do 20 miles I need to keep my cruising speed right down. This morning I drove 7.8 miles to Tesco to buy very little, I just wanted to drive. It was a great trip and I could drive it as a sports car, accelerating and braking hard. Pity I didn't take the Clubcard. If I'd spent more than £10 the points would have been worth more than the cost of the electricity! -Every little helps.

I see I have managed to post this in the wrong section-could someone clever move it?

Andrew.

I really would get a ammeter on things and not just rely on voltage sag, if you take a look here http://www.allaboutcircuits.com/vol_1/chpt_8/4.html it shows a basic way of making and calculating a shunt based ammeter.

Or splash out on a DC amp clamp, I bought one and find it really handy to be able to measure DC amps without needing to break into the circuit......... trouble is they arnt cheap.

I've moved this thread into "cars vans etc" as its like a review if its not where you'd like it just shout.

ChrisB

Good to see what real life achievements are like.
Any chance of coming up to see the trike? I would be interested in talking with you about the hoops you need to jump through to get it road legal and how you got started.

I am begining to think that it is highly unlikely I will be able to afford to get my MR2 to do what I need and that a much lighter vehicle, a reverse trike, would give me more of a chance.

Really great to meet you and your trike and many thanks for the chance of a drive in it, so much fun and definate ev grin (though it could have been mistaken for a grimace against the wind for lack of a helmet )

I have really been convinced that I could build a trike as easily as I am building my tractor and then get better range and performance then I could afford with the MR2.



Anyone want an MR2, less ICE parts?