I took the Lectra out for a long spin this evening - to Palo Alto and back, I believe that's 10 miles. FWIW at the end of the ride the bike became very sluggish and the 12v system (lights) cut out a couple times. The pack measured 59 volts by the time it got into the garage, meaning it dipped below 12v per battery.
Anyway, what I'm curious for advice about is proper controller behavior during a near-emergency-stop.
On one occasion something happened (?? the light changed ??) when I wasn't expecting it and I had to do a rapid stop. The brakes did a halfway decent job of stopping the bike...but... I had my hand on the throttle with the throttle turned a bit. That gave a little bit of power through the controller and I wasn't stopping very well, then I took my hand off the throttle (keeping the brake pulled) and the power came off the controller and the bike stopped very well.
Okay.. I shoulda rolled my hand off the throttle first... yeah, that's true.
On my EVT 4000 when you operate the brakes the controller automatically cuts power to the motor. Maybe that taught me some laziness, I dunno.
The brake levers both have switches in them, meaning it would be simple to fix it so the brake levers controls some kind of circuitry that tells the controller to cut power to the motor. So, that would mean no burnoffs but so what.
I think I just figgered it out ...?
One way is to make the brake switches turn off the key switch connection to the controller. On the alltrax, this actually turns it off. So I am a little concerned about that but maybe I'm being a worry wart. I'm not even sure just what the worry is.
The other idea I just thought of is for the brake switches to control a relay - the relay causes a 10,000 ohm resistor to switch into the throttle circuit, making it appear the throttle went way low. Or maybe just disconnect the throttle.
Take a look at their suggested wiring diagram:
http://www.alltraxinc.com/files/Doc100-047-A_DWG-AXE-PermMag-wire-dia.pdf
It shows a "foot switch" which is tied into the throttle on a golf car.
The same connection could be used with a brake switch. I don't think killing the power to the controller will be a problem.
You could also tie the brake switch into the throttle.
Whether you can successfully insert or substitute a resistance in the speed control circuit when activating the brake depends entirely how the speed control is done. If it is a 2 wire variable resistance type (0-5k for example) then you can. I have done that. But not so straight forward for "active" speed controllers, such as hall sensors.