[SyCo]

Hi all,

I've just bought an unfinished project started by someone else. This will be my first EV. I do my own mechanic (including engine swaps) and I'm a computer tech so I know many things about programming. So here how it goes...

Car:
2002 Hyundai Accent LC (3 doors, 5 speeds manual tranny)
Weight: 2190lbs (without batteries)

Controller (AC):
Curtis AC 1238-5601
36-48V, 650A max (210A 1hr)
with 1311 LP Handheld Programmer

Motor (AC):
Prestolite Asia ASDA 4004
15.5Kw, 30.3V, 405A, 1735RPM

Drivetrain:
custom adapter/mounting plate
custom flywheel (bearing supported) adapter shaft with a gear
pinion gear on the motor output shaft
chain driven (motor-flywheel) with 1:2 ratio to compensate for low motor RPM and theorically providing 3470 rpm at the flywheel.

Batteries:
None chosen yet (well, currently using four old 12V lead acid for test purpose)

Project Status:
The mechanical part is already installed and running. The motor mount will need some modification but that is no big deal for now. I will also need to do the power-brake part (vacuum pump). Most of the 4/0 gauge wiring is also done including a contactor but I will need some fuses for safety. I will also need a DC-DC converter to feed the car 12V system.

I'm now doing some tests with controller programming because the previous owner did not have all required information and I want to make sure the motor and controller operate adequately. I also know that this setup will NOT give me similar to ICE performance. It's a new project basically for learning purpose with EV. I would be glad if it could reach 35-40mph and be able to do 12-15 miles with a charge.

ok, now some questions :
Am I ok to assume that 48V x 210A = 10,080W (13.5Hp) will be the available power for my car ?

I am not familiar yet with Lead Acid battery, can they provide 150-200A for 15 to 30 minutes without overheating ?

I will look at the wiki and all the guides, but anyone wants to evaluate my theorical top speed and also maximum distance if I use good AGM or deep discharge batteries ? What type/capacity should I use for my 12-15 miles target ?

Thank you all, I will post pics tonight!

[major]

Originally Posted by SyCo

Am I ok to assume that 48V x 210A = 10,080W (13.5Hp) will be the available power for my car ?

Hi Sy,

First off you have figured electrical power from the battery. And at 210A, the voltage will sag at least 3V, more depending on the battery type and size. Then you have to account for the losses in the controller, motor and drive train. Roughly that combined efficiency will be on the order of the hp to kW conversion, ~.75. So, 45V * 210A = 9.45kW giving you about 9.5 hp to the drive wheels.

Realize this is the rated power from your controller. Peak power will be higher.

I am not familiar yet with Lead Acid battery, can they provide 150-200A for 15 to 30 minutes without overheating ?

Pb-Acid batteries large enough to give you the stated range at 50% DOD should be able to do that current without heat issues, IMO.

Good luck,

major

[SyCo]

thank you major

Time for some pics:

The car


Engine bay (12V battery during tests only)


Adapter plate and chain (top view)


Tranny adapter and chain (bottom view)


Controller (mounted were ICE rad was before)


Motor label


Don't worry about rust seen in pictures. The car sit for 2 months outside waiting to be sold. It's only on surface.

[bliksem]

I will do away with the 2:1 ratio. Considering your low (and realistic) speed expectation, rather run the car in the highest gear if even possible with
that "small" motor.

Is there only one bearing on the adapter plate? If you are keeping the clutch
the flywheel will wobble very soon. Also the transmission input shaft is not designed to take the weight and overhung load of the flywheel , your motor or
ICE is supposed to take the load. Modify the adapter plate and mount the motor
directly on the transmission.

There might be other reasons why the previous owner abandoned the project.

[dtbaker]

wow, that motor is HUGE considering the output! but at 48v, I guess that's what your gonna get. depending on how much rear seat and cargo area you wanna give up you could go with 4 big 12v sweeper batteries, or 6 good 8v golf cart batteries for a little more range. I have had great luck with us batteries (see http://www.usbattery.com/)

The chain drive would have me pretty nervous... I rode in a home-brewed EV with 3 small motors chained together, and it was LOUD with those chains flying around!

Depending on funding, you might wanna yank out this (failed?) drivetrain and go with a simple DC setup at 96 or 120v for better drivability?

[SyCo]

Originally Posted by bliksem

Is there only one bearing on the adapter plate? If you are keeping the clutch
the flywheel will wobble very soon. Also the transmission input shaft is not designed to take the weight and overhung load of the flywheel , your motor or
ICE is supposed to take the load. Modify the adapter plate and mount the motor
directly on the transmission.

There is one outside and one inside also. It seem pretty robust to support the flywheel instead of the ICE.

Yes I could modify the adapter plate but for now I will try to limit the motor RPM to around 3k and that will mean 6k at the flywheel.

This is my first project to learn the base, the programming, the battery, the charger... I've got that car pretty cheap and I want to start somewhere without to much modifications.

In the future (I should say in my dreams), what I want, is a street legal "monster" like John Wayland's White Zombie... but I'm a long way from there regarding money and experience so I must begin somewhere. But in my previous car, in about 4 years, I went from a stock 93 Civic that cost me 1k$ and ran the 1/4 mile in about 18sec all the way up to a drag ready 19k$ custom Civic that run 12.9@105 in N/A form at the drag strip. (all done by myself including engine swap)

Originally Posted by dtbaker

wow, that motor is HUGE considering the output! but at 48v, I guess that's what your gonna get. depending on how much rear seat and cargo area you wanna give up you could go with 4 big 12v sweeper batteries, or 6 good 8v golf cart batteries for a little more range. I have had great luck with us batteries (see http://www.usbattery.com/)

The chain drive would have me pretty nervous... I rode in a home-brewed EV with 3 small motors chained together, and it was LOUD with those chains flying around!

Depending on funding, you might wanna yank out this (failed?) drivetrain and go with a simple DC setup at 96 or 120v for better drivability?

Thank you for the batteries recommendation... as for the chain I don't know yet but I'm not worried too much because I will not go very fast and I will lower the motor RPM and use a different gear if needed.

For the drivetrain, I thing that I will keep that AC setup for now. Time and tests will tell if it's "drivable".


Thank you guys... any comments welcome !

[bliksem]

How far are the bearings apart?
Have you actually ran the flywheel at 6000 RPM?
You might still damage your transmission meaning more costs and more time lost.

[icec0o1]

Yes I could modify the adapter plate but for now I will try to limit the motor RPM to around 3k and that will mean 6k at the flywheel.

You'll get 6k at the flywheel but at half the torque. And 6k rpm in 5th gear will be like 100mph+.

It'd be very inefficient to go from 3k rpm to 6k rpm back down to 2k rpm in 1st gear. But I understand that you don't want to mess around with it since it's already built. Since you only have 25hp or so max power, I don't think your transmission will break from the tension of the chain so you should be okay driving it around. It's just not the most efficient design.

[SyCo]

Originally Posted by bliksem

How far are the bearings apart?
Have you actually ran the flywheel at 6000 RPM?
You might still damage your transmission meaning more costs and more time lost.

I don't know I haven't removed anything yet. For the 6k see below.

Originally Posted by icec0o1

You'll get 6k at the flywheel but at half the torque. And 6k rpm in 5th gear will be like 100mph+.

It'd be very inefficient to go from 3k rpm to 6k rpm back down to 2k rpm in 1st gear. But I understand that you don't want to mess around with it since it's already built. Since you only have 25hp or so max power, I don't think your transmission will break from the tension of the chain so you should be okay driving it around. It's just not the most efficient design.

Okay , that is what I thought about the torque. I'd prefer to run the motor at low RPM to gain max torque (see specs sheet below) but someone suggested that I run it higher ?! *.

What I was told by the previous owner is to run at 1500-1700 rpm to have max torque and the 1:2 ratio would provide ~3000 rpm at the flywheel so in 2nd or 3rd gear I would be able to drive at reasonnable speed.

Now I'm a bit confused

* see my other thread for other recommendations I've received: http://www.diyelectriccar.com/forums...ad.php?t=38066

[bliksem]

I did not mean that the torque will damage the transmission , but rather the
vibrations and run out. Judging from the quality of the welds I will undo as much as possible.