Tilt switch for master battery disconnect relay (contactor)

[Dougt]

Hi,
I was wondering if anyone has played with putting a tilt sensor (few dollars from digikey) circuit in series with the master battery switch. The motive is to disconnect the battery in case of a crash. Two fears, the throttle gets stuck on, either mechanically our through a short and the bike tire takes some extra skin off, or more likely, the battery cables/mechanical connections, etc short out and a fire ensues.

Most of these allow a range of tilt before engaging...+/-10 deg or +/- 45 deg. Now you may say, I tilt my bike when cornering and I don't want to crash from the sudden motor cutout during a lean into a corner, but that wouldn't happen as the tilt switch can't tell the difference between gravity and g-force. Unless you lean way over your frame during cornering (ie hold the frame somewhat verticle and while you hang off to the side...common in motorcycle racing, not so much in bikes).

Any thoughts...is this a good idea or just asking for trouble?

 

[Gregory]

Many cars have an Inertial Switch to cut electric fuel pumps in case of an accident. In Australia all converted EV cars must have one to disconnect the main traction pack if there is an accident.

No idea if they would be suited to a bicycle due to the vibration. And I don't really see the need, but if you see a need for a tilt switch, go for it!

 

[fechter]

Maybe you could find one of those from a junkyard. I don't know how they work but the major auto manufacturers probably put a lot of thought into it.

A seat switch is another idea. Not good if you stand on the pedals though.

 

[dnmun]

i think the drag and race boats have a kill switch on a lanyard that disconnects the power when the driver is ejected from the boat and the lanyard goes overboard with him/her.

 

[Raged]

I wouldn't. .. I was riding and got hit with a crazy crosswind... tilted 45 degrees and if I didn't punch the throttle to maintain speed, I'd be banged up pretty bad. Stick with a fuse 20A higher than your battery/controller can take.