Even after getting the EV-1 to work, we decided a "plug and play" golf cart controller would be easier for testing/development of the conversion. (It's not really plug and play, but far easier to set up than the EV-1.)

After haunting eBay auctions for a while, I got a great deal on a 225 amp Curtis controller from a Club Car golf cart.

It turned out that Curtis stayed in the car well past the "testing" phase, even though it's an understatement to say it wasn't a very powerful controller, even a small car like a Geo Metro.

Let's do the math: 48 volts x 225 amps = 10,800 watts. 746 watts per horsepower gives us 14.5 hp. (For comparison, the Geo's gasoline engine was rated for 55 hp.) Account for overall system efficency of about 75%, and that figure becomes 10.9 hp.

With the ForkenSwift weighing in at 2070 lbs post-conversion, you start to get a picture of the kind of driving "performance" 225 amps represents! How about 0-50 km/h (30 mph) in 36 seconds, flat out?

On top of that, 225 amps is the peak rating. The controller will only deliver that much juice when it's cool. Once it has been on for a while, it progressively ramps down peak power output to prolong the life of its electronic guts.