Lawrence Rhodes via EV wrote:
I had a Jet Courier truck using the same controller.  It was reliable.
However a simple Curtis/Chopper controller is much easier to set up and I bet
someone would donate one to Gramps if asked. They are also more efficient.

The EV-1 is pretty efficient; notice that it has no fans or heatsinks. There is also a "bypass" mode where it closes a contactor so it's simply straight through to the battery (100% efficient).

The hangup is that the EV-1 has no input filter capacitors; so nothing prevents the battery from seeing its pulsing on/off current. This didn't matter with huge industrial batteries. But it's hard on small batteries, whose Peukert exponent means that their amphour capacity is less when drawing (say) a 0a - 200a pulsating current instead of 100a continuous current.

Modern controllers use a big bank of electrolytic filter capacitors on their input. They also run at 15 KHz or more, which reduces the size of the capacitors needed. The EV-1 runs at more like 1.5 KHz, so it would need 10 times more capacitance to accomplish this filtering.

In computing, the mean time to failure keeps getting shorter. (Alan Perlis)
Lee Hart, 814 8th Ave N, Sartell MN 56377,
Please discuss EV drag racing at NEDRA (

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