Looking to start an EV Project, Needing advice

[Mad Professor]

Good day all.

I am looking at starting an EV project soon, but being a total newbe to the EV way of life I am going to need a fair bit of advice as I go along.

I am based in the UK, So I am trying to source all needed parts from within the UK where I can.

The donner car that I am wishing to use is a Peugeot 205 GTi, aprox stock weight 875-900Kg's.

The idea is to keep the standard running gear, and gearbox & cluch.

I am not looking for high speed or long range, as I only live on a 25x20mile island in the UK, most roads around me have a speed limit of 30 to 40MPH.

As I yet I have not brought any parts for this project as I need to work out what I need to get.

I guess the main things I need to look at are the main drive motor and controller.

With regarding to the drive motor I have been looking at getting the motor for a disused milkfoat that is local to me I have found out that the motor rated at 9KW @ 48volt, running speed of 1600RPM.

I have been looking into what gearbox to use, the standard 205 1.9 Petrol 5speed Gearbox would give a max speed of 34MPH, but if I was to fit the 205 1.8 Diesel Gearbox, that would give me a max speed of 42MPH.

So back to the drive motor again, so if it's 9KW @ 48volt thats 187.5amps right?

Is this the max current this motor will draw, and what rating fuses should I buy for use with this motor?

I am sure I will have more and more questions, as I get ready to start this project.

Thanks for your time.

Best Regards.

[Ryland]

Most motors have continues amp ratting and that is most likely the 9kw ratting that you are seeing, often times the peek draw of the motor can be 4 or 5 times that, you might see that peek draw while starting from a stop or going up a hill.
personally I think 48 volts is too little for a full size car, my 1,400 pound electric car is 48 volts and it has a top speed of around 35mph and slows down to about 25mph going up hills with it's 6kw motor altho your motor might be heavy enough to bump the voltage up if you are only running it for 10-15 minutes at a time.
I have a slow blow 300 amp fuse, this allows it to draw over 300 amps for a fraction of a second, I've seen it draw over 400 amps a few times and have not blown a few yet.
It sounds like the Diesel gear box is going to be the way to go if you use the motor you spoke of.

[Daox]

I agree with Ryland. You'll want to use more than 48V to get around. If you double the voltage to 96V (which is most likely not a problem for the motor), you also double the rpm of the motor (assuming its a series wound motor), so you can get 3200 rpm out of it and 18 kW @ 186A. This will reduce the amp draw for the same power and really help out your battery life.

What kind of range were you looking for?

[Mad Professor]

As for range as I said in my 1st post I live on a 25x20 mile island, and most of my trips are about 10-15miles each way, So if I can get a range of 30-40 Miles on a charge I will be more then happy.

I am still trying to find out more details about the drive motor, but having a quick look on the motor I could not see any plate with the details, I had to contact the firm that makes the milkfloat, for the details in my 1st post.

I don't know what type of DC motor it is, but it has four power terminals, if that helps at all.

[Bigswampthing]

I used a similar four post "sep-ex" motor out of a fork lift. Also, do your self a favor and get rid of the clutch completely if you can. Experiment on weather or not you can shift the car with out the clutch. Remember you can add batteries after you get the car running. Just buy equipment with some room for expansion.

[Ryland]

If all 4 posts on the motor are the same size then you most likely have a series wound motor, if there are two large and two small then it's most likely a SePex motor.
Either way, if you are going to run a voltage higher then the motor is designed for you are most likely going to want to add some forced air cooling to the motor, this can also be used as "heat" altho it's not going to kick out alot of heat like a gas engine does but it will give you a little warm air at times but mostly it will help the motor last longer.
It sounds like you have a decent start and more questions?

[Mad Professor]

I don't know if the posts on the drive motor are all the same size but they are marked, A1, A2, D1, D2.

I hope to be having another look at the milk float again at the end of this week or the start of next week.

The milk float in question has 24x 2volt 200ah lead acid batteries, and a spegel 48volt 24cell 30amp charger unit.

Due to the size and weight of the lead acid batteries I don't yet know if I will be able to use them, I will have to wait unto I have removed one to see the true size of them.

[Daox]

30-40 miles per charge really puts you in lithium territory IMO. You will be hard pressed to get that out of a lead acid pack. I wouldn't even consider using the float batteries. You need to boost the voltage if you want to increase the efficiency of the system.

[Mad Professor]

I know running at a higher voltage would be much better, but this is my 1st EV project, as still very new to things, so I just want to start low and work up.

Well I ending up buying the milk float for £200.00 today, and started stripping it down, after taking lots of pictures of all the wiring.

So far I have removed the following.

1x Electrofit Zapi Ltd High Frequency 48volt Controller.
1x Zapi S.P.A Foot Peddel Box.
1x Albright DC182B-256 48volt Contactor.
1x Albright SW181B-152 48volt Contactor.
1x Albright ED250B-1 Emergency Disconnect.

The motor is out but I can't find any plate with all the details so I will have to contact towrite to makes the milk float for more details.

I still have to remove all the batterys and power cables, but that will be done over the next week.

I would like to bench test the motor, can I test it with just a 12volt car battery, and how do I connect the motor?

As it is ment to be a series wound dc motor, for just testing is it a case of connecting battery (+) to A1, connecting A2 to D1, and then connecting D2 to the battery (-)?

Thanks again.

[Ryland]

Originally Posted by Mad Professor

I would like to bench test the motor, can I test it with just a 12volt car battery, and how do I connect the motor?

As it is ment to be a series wound dc motor, for just testing is it a case of connecting battery (+) to A1, connecting A2 to D1, and then connecting D2 to the battery (-)?

That sounds right, I've used automotive jumper cables for testing motors, you don't want to use more then 12v for testing the motor unless it has a load as it can over speed the motor and damage it.
what is the stock top speed and stock loaded weight of a milk float?