Sabvoton mqcon lack voltage

Joined
Apr 9, 2020
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12
Hey, just connected my svmc7280 and connected via Bluetooth to the mqcon app and I'm getting a "lack voltage" error from the app despite the display confirming that the controller is in fact receiving about 83v. I've check the low voltage cutoff and its set to 40v so that's not the issue. The motor has been connected to the motor and the battery but behaved exactly the same when only connected to battery. Any ideas?
https://ibb.co/BKjc9nc
https://ibb.co/LRDNcDJ
https://ibb.co/BTV0fSp
https://ibb.co/16Xp23R
https://ibb.co/VNtJT1d
https://ibb.co/DpdsjBK
 
Try unplugging all the connections and check that the pins are straight.

Jonno
 
I had same issue with my controller at first.. if you use the Bluetooth adapter you need to disconnect the 3-pin plug going to the lcd connector and power up the controller with the lcd
 
Black6spdZ said:
I had same issue with my controller at first.. if you use the Bluetooth adapter you need to disconnect the 3-pin plug going to the lcd connector and power up the controller with the lcd

that was it, thankyou :D i have no idea what the issue was but you've solved it.
 
Black6spdZ said:
I had same issue with my controller at first.. if you use the Bluetooth adapter you need to disconnect the 3-pin plug going to the lcd connector and power up the controller with the lcd

How do you power it up with the LCD disconnected?
 
PlanetDad said:
Black6spdZ said:
I had same issue with my controller at first.. if you use the Bluetooth adapter you need to disconnect the 3-pin plug going to the lcd connector and power up the controller with the lcd

How do you power it up with the LCD disconnected?
I believe the poster meant to disconnect the *bluetooth* from the LCD connector of the controller, and then using the LCD to power up the controller (by plugging the LCD back in to that connector). But I don't have one to verify this with, so I can't say for certain.
 
There is a 3 pin connector on the controller that is plugged into another from the controller. Unplug it and your bluetooth and app will work. Don't forget to plug it back in when you're done.

plug wire colours yellow, green, brown to yellow, green, black

Jonno
 
TannyFordas said:
Hey, just connected my svmc7280 and connected via Bluetooth to the mqcon app and I'm getting a "lack voltage" error from the app despite the display confirming that the controller is in fact receiving about 83v. I've check the low voltage cutoff and its set to 40v so that's not the issue. The motor has been connected to the motor and the battery but behaved exactly the same when only connected to battery. Any ideas?
https://ibb.co/BKjc9nc
https://ibb.co/LRDNcDJ
https://ibb.co/BTV0fSp
https://ibb.co/16Xp23R
https://ibb.co/VNtJT1d
https://ibb.co/DpdsjBK

I have a similar problem. It says lack voltage on the app and I don't see what could cause that when the head set reads 73.v.
 
I left the light on mine and drained it down to around 66v and charged it to 83v and it sorted the issue
 
I have the same problem, no lcd at all so not that, every time I try and put voltage settings in they go straight back to zero after 3 seconds, even if I press ok save. Worst controller I've ever had and the price of them makes it even more sickening 😪
 
I have found the problem, a little surface mount diode has blow, it say D4 at side of it on board, would anyone know what value it is as I haven't got a clue, I suppose I could short it across but would ideally like to replace it with a new one. I will try and include a picture.
 

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What circuit is it in? (where does each end of it lead to?)

Note that parts like that are often used as "fuses" so that if something goes wrong downstream, it doesn't destroy everything in the circuit. So it is possible there is something wrong "past" the diode that caused it to fail. (it could just be a bad or even wrong part...but it's worth a check of the circuit).
 
I’m having the same type of issue. I unplugged several plugs off of controller, including Bluetooth. I dont have the lcd version of the sabvaton 72150. I am getting error code “controller overheat store hall” and then after 1 second it switched to “lack voltage” despite battery being at 83.6v. Also, the bike worked perfectly when I put it away last. Charged it today and when I turned it on to ride I got these codes. Not in the middle of a ride. Any help would be greatly appreciated.
 

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Since the display first showed a bunch of nonsensical numbers, perhaps the settings are corrupted. I would recommend checking all of the settings in the controller to see if any have changed from when you first set it up, especially the battery voltage related ones, since the Lack Voltage means it sees your present battery voltage as too low.

Otherwise, try the steps given at the beginning of this thread that worked for the original poster.
 
There is a 3 pin connector on the controller that is plugged into another from the controller. Unplug it and your bluetooth and app will work. Don't forget to plug it back in when you're done.

plug wire colours yellow, green, brown to yellow, green, black

Jonno
I don't have these connectors on my sabvoton I can contact with Bluetooth and get the same lack voltage but I do not have the programming connector to disconnect. What do I do to resolve this?
 
I had same issue of lack voltage. Cycled in and out of app. Left bike on few minutes with app off went back in app, app now getting correct readings from controller.
 
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