Handlebar On/Off Kill Switch

[dirtdad]

Per a recent thread, I am thinking that I should install an on/off kill switch on my eBike, esp as the power goes up, as a safety measure to protect against a runaway system.

My question is: what is the best way to wire it?

I could just put it in line a throttle wire. Are there any failures this will not cover? I would hope to not run battery power up to the handlebar. Perhaps the switch would drive a battery relay/contactor? That seems pretty complicated. In my case, the batteries will have a switch anyway, close at hand, but not on the throttle. Perhaps I could look at it as a 2 - phase emergency cut off. If there is something that killing the throttle won't fix, I reach down lower and kill the batteries.

Well, 3 phase. I consider massive braking power phase 1

 

[fechter]

Just killing the throttle signal or control voltage is not good enough for a brushed controller.

You should have the switch operate the main contactor relay to completely kill the power to the controller.

If your controller shorts, the motor will go full throttle with no current limit. You will be pulling a wheelie before you can say oh-shit. The brakes may not be enough to stop it.

On my scooter, this switch actually kills the power to a small dc-dc converter that powers the relay coil and the lights.

 

[dirtdad]

...but for brushless a throttle switch is good, then?

For the Etek project it looks like a contactor is the only safe way to go.

 

[dogman dan]

Maybe a fuse holder could be put on or near the handlebars with a lanyard to the wrist on the fuse like the kill switch on jetskis? Just a thought, asuming a front hub.

 

[ngocthach1130]

If you use Power pole connector to connect your battery and controller together, you can tie a string to one side. Just give the string a yank to break connection. ^__^. Only thing to pray is the contact aren't welded together.

 

[MidniteTweeker]

Today was the maiden voyage of my electrified tadpole trike. While I'm not completely done or satisfied with it, my kill switch is a blade-type fuse/fuse holder in series with the on/off switch. I looped a small tie-wrap around the fuse body between the two terminals. Before I pulled it tight I looped a second larger tie-wrap through the first and then pulled both of them tight. Cut the tail off the small one, but left the tail on the larger one for use as a handle or anchor point for a pull cord. Cut a bit of extra clearance for the small tie wrap into the fuse holder and then put the fuse into the holder. Because it's a tadpole, all of this is behind the seat. My intent is to route the pull cord under the seat to the front edge near the bottle carrier where I can reach it with either hand.

MT

 

[docnjoj]

Welcome fellow triker! Can U post some pics?
otherDoc

 

[dirtdad]

I like the lanyard idea from jet skis. If you get thrown from the vehicle somehow you might not have time to hit even a handlebar switch, and you could have a runaway bike. I presume this is the idea behind the jet ski switch. Last thing you want is your jet ski heading off to sea without you, or running aground in the rocks, or headed toward a swim beach. By combining the handlebar switch with the lanyard you get both functions without having two switches.