THIS IS A LONG ONE...
Let me start by saying, that the only real meat and potatoes regulation I have come up with looks like this:
1) Throttle (Single Point Failure)
2) Battery (Charge, discharge, and fire)
"The throttle shall be interlocked with a secondary, such that more than just the analog input can propel you forward" (as in some cases there is a clutch or tranny - so motor current not primary)
This is the situation where either a drip of water, a hair of wire, a failed POT, a failed Hall, a loose magnet, a broken spring, or some other failure in the throttle output or controller throttle input causes current to be sent to the motors when it is not wanted. This is VERY SERIOUS... as I have learned with two runaway bikes and... now that I am riding the fastest Zero around... eh...
Either a switch at the bottom of the throttle which opens with a broken throttle
A pair of differential hall signals
A secondary "foot pedal" or other switch like that found on a fork lift seat...
This is a REQUIREMENT and it is not found in all OEM vehicles... especially those found... a few years back.
"The battery shall not catch on fire in the event that a user attempts to apply a charge voltage (or current) in excess of what is called for - so within reasonable limits - a contactor or reliable switch of some kind guarantees that charge will be terminated".
This should apply to a window of reason... such that yes... if someone applies 1000V to a 30V battery fire may occur... but if someone applies a 100V charger to a 36V battery... it can charge up in CC mode then blow open before any cells go critical.
We must bound the upper limit else components get really expensive. So... some percentage or some absolute value within a range... like:
Ebikes - can handle up to a 120V charge input without catching fire
Motorcycles - can handle up to a XXX charge input without catching fire
Cars - can handle....
Same for discharge - but only in the case where it could case fire - so mostly temperature sensor based.
ANYHOW... why I am blathering on about this is that I had my second runaway last night.
It is posted somewhere here on the sphere.
I was running a Tadpole trike with a hall throttle
I was riding hard and pulling on the split-twist throttle
The throttle came loose...
The design of the hall throttles we use depend on the magnet being ON the hall sensor for 0% throttle output (1.2V or whatever)
When the throttle pulls away, the magnet pulls away, and you get FULL THROTTLE.
As you know... my bikes are POWERFUL... and that was a real handful to get control over.
The controller was not bound such that an over-throttle voltage could be detected... as with a higher end controller like a Sevcon... that accepts throttle inside of a window only:
Example: Sevcon Throttle voltage, 10V
Will accept 0.5V to 9.5V
0V to 0.5V equates to dead band
Above 9.5V equates to Fault
So... that is an example of a throttle based runaway situation.
I literally ripped my throttle apart during "normal use" and it resulted in FULL THROTTLE>
Last night I resurrected an Ebike out of the pile.
It had a controller I am not familiar with... sketch is how I would describe it... but in reality the components inside were high end. There were no expenses spared on caps, connectors, etc.
This controller had sat in the rain so long that the power switch rusted completely (I have pics of all this)
Some corrosion must have occurred in the throttle input section... and I suspect I know how it happened
DISPLAY THROTTLES - UNACCEPTABLE
Wiring Order: 5V, GND, THrottle, Full Pack Voltage
So... on this tiny JST-SM connector... with only 0.1" of space... we have 50V riding right next to our 0-5V throttle input
Yea... so this controller "runs away" in an inconsistent and unpredictable way.
It will be fine for 5 minutes... then all of a sudden it will start applying 30% or more throttle
If the throttle is removed via the connector... it will still keep going
Lucky on this bike that the front and rear hydraulic brakes, along with the heavy frame and second rider (two up), along with the low current limit, along with wet tarmac... allowed us to overcome the runaway... BUT IT HAPPENED.
Had it happened on one of my "serious ebikes" someone would be broken in the hospital.
Which... brings me around to the Zero Motorcycle.
I am currently riding a race prepped 2013 SR.
It is pimped out with a drilled motor and whatever the last "track day" guy could do to it.
IT IS POWERFUL
Like... THIS kind of powerful (time 1:30
Increasing battery voltage and controller current limit will result in a non linear experience