LCD3 and Alarm with LOCK function?

[crazymaster]

Hello!

I have 72v e-bike.
I had a 72V bluetooth controller with LOCK engine function which can blocks the engine and it cant move. You can enable the option from settings.
OR also i had alarm which have LOCK option from the remote control... so it was awesome... i never needed to bring lock with me(the bike is 50+kg so nobody can steal it when rim is blocked)

Here is the controller with the lock option:
https://www.ebay.co.uk/itm/36v-48v-60v-72v-40A-BT-PROGRAMMABLE-E-BIKE-ELECTRIC-BRUSHLESS-MOTOR-CONTROLLER/163661036202?hash=item261af53aaa:g:sVgAAOSwWm1cwwzI

Here is my alarm:
https://www.ebay.co.uk/itm/48V-72V-Electric-Scooter-Bike-Anti-theft-Alarm-Security-System-Remote-Control-/283331619883

The problem is that i want LCD3 screen, so i just bought KT controller, but it doesnt have the LOCK function...

Do you think that we can add this option to it? Probably some kind of connecting the hall sensor or the engine cables to the alarm and it may work?
I will play with that next days, but if you give me any tips or if somebody already do it.. please help me

Here is the link of the controller i got:
https://www.aliexpress.com/item/72V-2500W-3000W-60Amax-Brushless-DC-Motor-Controller-Ebike-LCD3-KUNTENG-Sine-Wave-Controller-KT-LCD3/32992278450.html?spm=a2g0s.9042311.0.0.79274c4dSmLAOa

 

[vfr400]

All it does is short the phase wires. You can do the same by adding a switch across any pair. The more pairs you short, the more it locks the wheel, but one pair should be enough to make the bike unrideable. It needs to be a switch with a decent current rating. I would go for at least 10 amps.

You can try it. Switch the bike off and disconnect the motor phase wires, then hold two of the phase wire bullets together and try to turn the wheel. If it doesn’t have bullets, use a piece of wire to short any two phases.

 

[crazymaster]

I will try it.
Anyway... usually when battery is very low the power is lower... so if i do it in the way you say it should be strong all the times, right?

so i will need to use a relay to be able to make it to work with the alarm and remote, not adding a switch ?

 

[vfr400]

The function is independent of the battery. If you do a direct short of the phase wires without the controller and battery connected, you'll see how effective it is. You'll struggle to turn the wheel.

The controllers that have the lock function need at least some charge in the battery to work because the controller has to be powered on to do it. Basically, it shorts the phase wires electronically by opening the right combination of MOSFETs. To keep them open, it needs a small amount of power. To keep the controller switched on takes something like 4W.

If you have a direct drive motor and you blow a MOSFET or more in the controller, the first thing you notice is that the wheel is difficult to turn because you get the same short between the phases. People that don't know better apply their logic that the motor is faulty and look for a replacement, but if they were to disconnect the motor from the controller, it would go back to turning easily, like before.

 

[Gooseman]

All it does is short the phase wires. You can do the same by adding a switch across any pair. The more pairs you short, the more it locks the wheel, but one pair should be enough to make the bike unrideable. It needs to be a switch with a decent current rating. I would go for at least 10 amps.

You can try it. Switch the bike off and disconnect the motor phase wires, then hold two of the phase wire bullets together and try to turn the wheel. If it doesn’t have bullets, use a piece of wire to short any two phases.

If i put a switch between 2 phase wires to short them. Then if the battery/display is powered up is this not going to blow something?

 

[vfr400]

If i put a switch between 2 phase wires to short them. Then if the battery/display is powered up is this not going to blow something?

Only if you open the throttle or turn the pedals. Why would you leave the LCD switched on if you're locking your bike?

 

[Gooseman]

Only if you open the throttle or turn the pedals. Why would you leave the LCD switched on if you're locking your bike?

My memory is not the best and was thinking more along the line of getting back on my bike and pedaling before remembering to flick the switch. I also tried touching the 3 bullet connects together but didn't seem to make a difference in rotating by hand is this because i have a geared hub or a sign something is wrong?