Generic ebike throttle ignition switch current rating?

Turbine User

New Member
Region
USA
Hello, I'm working on a bike project. It's not an ebike, but I found an ebike throttle on Amazon that looks like it will work well for what I'm doing.


This throttle has a keyed ignition switch. On a normal ebike I'm guessing that this would just be a signal wire to a motor controller since the wiring to it is a pretty thin gauge. But I was wondering if anyone knows about how much current this ignition switch can handle. I took the throttle apart, and the switch has no markings on it that tell me what it's rated to, or even a part number that I could look up to try to find the amperage rating. For what I'm doing I need to run a small fuel pump and an electronic telemetry device. I'm just wondering if I could get away with running that directly through this ignition switch or not. Thanks.
 

indianajo

Well-Known Member
The ignition switches are designed to control the input of a bicycle controller, which is low current. Goes to the green wire of controller for some stupid reason. Plus to switch comes from the same feed that sources the throttle sensor.
I would use a nfet to run a fuel pump on 36 to 48 v. 1000 ohm resistor to gate of nfet from switch. source of nfet to battery negative. Drain of nfet to fuse from fuel pump negative. Plus of fuel pump to battery plus.
Tab of nfet insulated by silicon washer to heat sink.
Or you can buy a $50 solid state relay.
 

JES2020

Well-Known Member
Region
Other
Hello, I'm working on a bike project. It's not an ebike, but I found an ebike throttle on Amazon that looks like it will work well for what I'm doing.


This throttle has a keyed ignition switch. On a normal ebike I'm guessing that this would just be a signal wire to a motor controller since the wiring to it is a pretty thin gauge. But I was wondering if anyone knows about how much current this ignition switch can handle. I took the throttle apart, and the switch has no markings on it that tell me what it's rated to, or even a part number that I could look up to try to find the amperage rating. For what I'm doing I need to run a small fuel pump and an electronic telemetry device. I'm just wondering if I could get away with running that directly through this ignition switch or not. Thanks.
If you can estimate the gauge of the wire, then look online for max amps that wire can handle.
Then you would need to know the amps you devices need.

For example:
Twelve-gauge wire is good for 20 amps, 10-gauge wire is good for 30 amps, 8-gauge is good for 40 amps, and 6-gauge is good for 55 amps,”
 

Gionnirocket

Well-Known Member
Region
USA
City
Y. O.
Hello, I'm working on a bike project. It's not an ebike, but I found an ebike throttle on Amazon that looks like it will work well for what I'm doing.


This throttle has a keyed ignition switch. On a normal ebike I'm guessing that this would just be a signal wire to a motor controller since the wiring to it is a pretty thin gauge. But I was wondering if anyone knows about how much current this ignition switch can handle. I took the throttle apart, and the switch has no markings on it that tell me what it's rated to, or even a part number that I could look up to try to find the amperage rating. For what I'm doing I need to run a small fuel pump and an electronic telemetry device. I'm just wondering if I could get away with running that directly through this ignition switch or not. Thanks.
Wire size can give you a hint but the current rating of the actual switch is really another animal. I'm guessing that it is designed to run low current / relay so that's what I'd do to run the accessories you're contemplating.
 

harryS

Well-Known Member
Use a relay as suggested. Ebike ignition switches are 18g wire intended to switch battery power to a low current circuit inside a controller.