Restricting AMPS/Current/Torque!

[MIOM]

I have a little electric trials bike which is 36v with a 750w motor. The control unit is 30amp and it runs on SLA batteries (3 x 12v 10amp).

The bike spins up a lot with my boy on especially in muddy conditions and so I wondered if there is a control unit I can wire in which would restrict the amps going to the control unit? Something variable which you could adjust from say 15-30 amps would be useful!

Anybody any suggestions/ ideas? Makes a change trying to restrict these things!!!

 

[dogman dan]

Actually, replacing the controller might be the best thing to do. Two decent options.

One, just buy another controller, say 20 amps.

Two, buy one that is compatible with a direct plug in Cycleanalyst. Then along with monitoring your battery, the CA can limit amps.

Third option, open the controller, find the shunts. They will often look like two or three staples in a row. They are part of the system that controlls the amps.
Cut one of the shunts. If you have two shunts, now you have a 15 amps controller. Later on, you can put a blob of solder reconnecting the shunt, and it will again be a 30 amps.

 

[MIOM]

Thanks for your response.

It's a new bike so have just pulled control unit out. It actually says it's 40amp. The control unit is an XK-022D. When I Google these they show as 30amp, which is a bit confusing, as it's definitely labelled as 40amps!!

 

[Drunkskunk]

You can cut the speed and power by 1/3 if you remove 1 battery and use a 24 volt controller like the XK-022C. Oddly, most of the brushed controllers from this line are called XK-022, and the last letter seems to designate the diffrence, but with no real logic. C is a 24 volt 30 amp. D os a 36 volt 30 amp, E is also, but with a slightly diffrent connector, But F is another 24 volt controller, with a diffrent plug.

 

[phil o' dendron]

wouldn't it be easier to modify the throttle signal with one of these switches
http://www.methtek.com/2012/07/03/universal-3spd-switch-works-with-any-controller/

was discussed in another thread, can't find it at the moment.

you can easily switch back to full power when out of the mud hole :wink:

 

[rp3]

You don't have to have a compatible controller to use a CA. Just get the external shunt model, it can limit the watts/amps while remapping the throttle curve to match. You can also swap between modes with a 3 way switch.

 

[gwhy!1]

I have a little electric trials bike which is 36v with a 750w motor. The control unit is 30amp and it runs on SLA batteries (3 x 12v 10amp).

The bike spins up a lot with my boy on especially in muddy conditions and so I wondered if there is a control unit I can wire in which would restrict the amps going to the control unit? Something variable which you could adjust from say 15-30 amps would be useful!

Anybody any suggestions/ ideas? Makes a change trying to restrict these things!!!

is this a oset ?... they have a adjustment pot that can restrict top speed but they have nothing to limit current. I made a add on circuit that allows to adjust the current from max to 0 , I think I posted it in one of my threads it was moddified from a original circuit from fechter, some info in this thread http://endless-sphere.com/forums/viewtopic.php?f=2&t=33963&start=45.

 

[MIOM]

Thanks for all the great replies guys.

Yes GWHY, it is an Oset. Do you have any further details on the mods you have done previously?