Thinking of converting my Volvo

[mechman600]

I have yet to do a conversion. I keep psyching myself up to do a high-end conversion (AC/lithium) on my wife's Toyota Matrix but I have a massive fear of project failure.

I bought a $400 winter beater a couple of months ago, a 1984 Volvo 244. All it does is get me to work and back. But I got thinking: why not do an ultra cheap conversion on this thing first? I know it is the worst possible donor car ever, but unfortunately (or fortunately?) I have sort of fallen in love with the car already. It is the worst beater I have ever owned. It is ugly. It always has me on edge because of imminent breakdown. But it's like the Top Gear Botswana Special where Richard Hammond falls in love with his Opel Kadett: I have sort of done the same. It's so uncool that it goes full circle and has become very cool.

Details: 3050 lbs curb weight. Aerodynamic as a barn. 3-speed auto with no lockup, so inefficient. I will probably try to find a used 6.7" motor. Possibly buy a new D&D ES-15-6. Maybe a Kelly 400A or 500A controller. I have access to a nearly unlimited supply of battery cores, many of which are still okay. I'm thinking 6 group 34 batteries for 72V. As my batteries croak I can continuously replace them. And 6-12V chargers.

I will need speeds of 35-40 mph on the flat and a range of 8 miles. My commute is exactly 4 miles. Slightly down hill on the way to work and uphill towards home. I will charge at work just to make sure.

Will this work?

[Ryland]

Go with a larger motor and don't use a Kelly controller, my 1,400 pound electric car has a 6.7" motor and goes 35mph on 48v and I could not imagine that motor moving twice as much weight around even at a higher voltage and at 48v I have a 650 amp Altrax Controller and I'm glad that I didn't go with a lighter duty controller as I've seen it hit 600+ amps a few times.
The more I read about Kelly controllers the more I am surprised that no one is dead and that they are still around, read up on them a bit and you will find people who have them fail, the only one that I have seen in person burned up causing the motor to power up, over spin and caused around $2,000 in damage to the motor, drained the set of batteries all the way down and ended up ruining them and the controller it's self had a hole burned in the side of it and of course non of this is the fault of the controller so to have anything done you would have to take them to court.

Do you know what your gear ratio is on the rear end? can you get away with a direct drive and use an electric forklift motor?

[mechman600]

Thanks for the advice. I did not realize that Kelly controllers were so shoddy. Their price is what lured me in. I know Altrax is a good product. I am hoping to find used parts for this venture.

My axle ratio is 3.54:1, according to what I can find on the internet. But I should probably check it by jacking it up and counting revolutions just to be sure.

I was thinking of keeping the transmission & torque convertor for their torque multiplication from a stop. I figured this would allow me to use the smaller motor. When do you hit 600 amps, are you starting off? If so, I assume that a transmission/torque converter would make it easier (less ampy) on startup. Correct me if I am wrong.

I have thought about going direct drive, but when it comes to finding a forklift motor, I have absolutely no idea where to even start looking. For direct drive, I assume that a 11" or larger motor is necessary, especially considering the weight of this car. In brand new motor terms, that's really expensive. In forklift motor terms? I have no idea. Do I go to a forklift repair shop and start to ask questions? I should search for a forklift salvage business.

I see an advantage to converting a rear wheel drive car (even more so if you go direct drive) is under-hood real estate. If you can jam the motor into the tunnel where the transmission used to go, you are left with a lot of room for 'stuff', whatever you want that to be. You can use the bonnet as boot space if you have stolen boot space for batteries.

[Ryland]

That gear ratio sounds a bit to high for doing direct drive, how about swapping in a manual gear box? automatics waste a lot of energy so most people don't use them, I've only met a few people who have tried and they all said that keeping the automatic was their one big mistake.
Sad to say but I don't think altrax makes a controller large enough for your car, their largest I think is a 72v 400 or 450 amp controller and higher voltage would be better and a 30 second or even a one minute rating of 500 amps or more would be the least that I would do.
I've seen 600 amps while climbing a hill and while starting from a dead stop on the flat.
As for sourcing a fork lift motor, I would start with scrap yards as they tend to sell metal, including motors, by the pound.
Also check out Ben Nelson's DVD on building your own electric car, cheap.

[tylermj23]

Is there anyone to convert a jeep grand cherokee?

[Ryland]

There are a few Jeeps on EVAlbum: Search Results but the Cherokee's that are listed are getting using 550 to 600 watt hours per mile with a 65mph top speed with a 120v system and 9" motor, to compare, put that same drive in a car and you will use nearly half as much energy and top out at 90+mph.

Compare to the Volvo's EVAlbum: Search Results and you will see people who are using 300 to 400 watt hours per mile.

[mechman600]

For the Volvo I am thinking of making an ultra-simple bad boy charger at first. I did some brainstorming today. Here is my idea:

Go with 108V pack voltage, 9 batteries. Run 120VAC through a 1500W dimmer switch ($60.00), a bridge rectifier ($2.00) and a 15A ammeter ($10.00). Current will have to be limited with the dimmer at the beginning of the charge, but once the batteries are charged, it should end up being close to perfect voltage that no control will be required. 120V/9 batteries = 13.33V

If this works, would it also work on a 72V or 96V pack? Just rely on the dimmer to control output? As far as I know, dimmer switches provide PWM voltage. No doubt they would generate a bunch of heat, so I would mount them in a box with a cooling fan.

Has anyone successfully tried this simple approach without accidentally murdering themselves?

[jakobnev]

120V is the RMS value, the peak voltage is 170V.

And i'd recommend you only consider alternatives that leave your car galvanically insulated from the electrical grid.

[mechman600]

Originally Posted by jakobnev

120V is the RMS value, the peak voltage is 170V.

I was wondering about that.

Originally Posted by jakobnev

And i'd recommend you only consider alternatives that leave your car galvanically insulated from the electrical grid.

Like through a transformer like normal (less death-prone) chargers?

[MetroMPG]

Originally Posted by mechman600

I have access to a nearly unlimited supply of battery cores, many of which are still okay. I'm thinking 6 group 34 batteries for 72V. As my batteries croak I can continuously replace them. And 6-12V chargers.

Wow. This is the motherlode! Lucky you.

We lucked out similarly with the ForkenSwift, in that whenever someone in the EV group in Ottawa was getting rid of their 6v golf cart batteries because they weren't delivering enough range anymore, we have been able to pick them up for not much more than scrap value. They still have value in a light car driven short distances in a small city.

We've changed packs something like 3 times now, and there's yet another "new to us" pack waiting in the wings. (OK, sitting on my garage floor.)

I will need speeds of 35-40 mph on the flat and a range of 8 miles. My commute is exactly 4 miles. Slightly down hill on the way to work and uphill towards home. I will charge at work just to make sure.
Will this work?

To put things in perspective, you can use the 48v/400A, 2070 lb ForkenSwift for comparison. It will eventually get to 60 km/h (40ish mph). But it's slow accelerating above, say 40 km/h. 0-50 km/h on the level takes roughly 20-25 seconds, flat out.

If you love your old Volvo, then go for it. You'll just have to compensate for the added mass with more batteries/higher voltage & more energy consumption.

Where to look for forklift motors? Call some of the forklift service places near where you live. That's where the ForkenSwift's motor came from.