Help with selecting new motor controller.


1 µW
Feb 20, 2024
So I had a client bring in an Escooter, he brought it second hand and it was not running, seams the battery and motor controllers were fried. I have replaced the battery and now need to source 2 new controllers, the scooter looks like an AKEZ SQ11 1000W and had two 1200W controllers at 48v in it, quite underpowered but I need to find something similar that can handle the NJAX controller on the handle bars as well as the DK-218 dual speed controller. Does anyone have some advice as im new to the Escooter scene.
Thanks in advance.
First, keep in mind that the only things we have to go on are what you tell and show us. ;)

What specifically do you mean by "underpowered"? For what usage, under what riding onditions?

If by "NJAX controller on the handle bars" you mean a display, it's fairly likely you'd have to get the original parts for that to work with them; that might have to come from the original manufacturer. At minimum it probably has to be the same brand and series, possibly the same model, of controllers as original.

Otherwise, there are a few "kits" out there for dual-controllers that include all the bits needed to make them run (which would replace the equivalent bits already on the scooter. You have to make sure the battery is capable of more than the total A (not Ah) of *both* controllers' current limits, or else the system will either cut out / shut down when both are used together and that much current is drawn, or the battery may be damaged.

What battery has been used for the replacement?

What did the original controllers not do with the new battery, and with the old?
Yea it seams I will need a new kit to get it working as I can not find the controller models out there at all, I will probly need new M8 cables for the breaks and light/ horn switch as well as they route through the same cable as the display and terminate at the 6 pin for the controller for 2 of their pins.
The battery wasn't exactly replaced, I asked the client what they wanted to do and they opted to get it refurbished, its resealed now so Im stuck with the assumption that they replaced the cells, but it reads the correct voltage now so it is at least working, and as for why I called it underpowered that was a mistake on my part the battery is underpowered, only 13AH but it is the original battery that comes with the SQ11, how it is expected to run 2 1000W controllers escapes me though as 13A for an hour seams very low for the purpose.
When I hooked the battery up after it was refurbished the display came on, and it would read the "speed" when I moved the scooter manually, the lights would come on when I flipped the switch but no power was delivered to the motors when I used the throttle the two motor controllers also smell of the magic smoke so something in them has blown for sure.
At 50A (guesstimated current for all 2400w of controller draw), it would mean the 13Ah battery has to be capable of at least 50 / 13 = 3.8 or about 4C. Most of the cheap ones can barely do 2C (or twice the Ah as current Amps), which for this one would barely be half of the required current, at only 26A, and that's usually pushing them hard. Without knowing what's actualy in the battery, you can only hope it can handle the load, and if it can't replace it with one that can.

If it was actually used in conditions that continuously drew 50A, it would be empty in less than 15 minutes. It would probably shut down before that from voltage sag under load, probably around the 10 minute mark. It's unlikely that it could be kept at full power very long unless they ride it up long hills or against strong headwinds, or ride fast enough.

if the controllers smelled like smoke, they certainly could have severe damage--the most common is FETs blown. But if those are blown, a common reason for that beyond simple overload is a motor problem or wiring between motor and controller, either of which will then blow up any new controller that is hooked up.

I'd recommend at least a minimal investigation into the inside of the controllers, to see what actually blew up and smelled smoky, and/or verifying the motors and wiring don't have any problems.
Yea that was my thoughts on why the battery seamed underpowered. Oddly enough the scooter is 1000W I believe the 1200W controllers are a new addition as the wiring connections aren't factory condition looking. And the battery that it has is the original, at least as far as I have seen with replacement.
I will check the motors and the wiring again but I do believe they are ok, the wheels spin freely, and when bonding the 3 phases together at the terminals the wheel is harder to spin.