CA 3.1 External power Jack and lights issue

When connecting my lights to Cycle Analyst 3.1 DC power jack, my MAC motor will start turning intermittently (gittering?) like the throttle is being slightly pressed.

I’m running 51V normal battery with 6-80V lights. Lights draw about 5W total. So within power rating. If I have only one light connected, the problem goes away.

Any suggestions welcome.

You lights are pulling additional current through the CA GND and Vbatt leads. The intrinsic resistance of the wires causes the headlamp current to impress a small voltage across the leads. In the case of the GND wire, this makes the CA end of the wire be at a slightly higher voltage than the controller end of the same wire. Since the CA is supplying the throttle signal to the controller and that voltage is relative to the CA GND, the throttle signal ALSO is raised by a small amount which the controller interprets as turning the throttle a tiny bit.

Your ThrO settings are set too close to the actual controller throttle input range limits.

Turn on the headlamps and re-do the adjustment for ThrO->MinOut as per the Guide section "4.6.2 Set Throttle Input/Output Voltages". Or - if you are just winging it, reduce it by about 0.1V or so.

That fixed it. Many thanks Tek!

Gotta love a solid answer/response like that!