Electric brake is now constantly on (Not related to light)
 

My ES2 started to act strange after installing the external battery (converting it to an ES4). It worked fine for a couple of days and then it started to do weird things.

First the power became unstable and kind of uneven. The next the brake is constantly on (the brake light is flashing) and it almost does not move forward when I try to accelerate. This is regardless of the lights being turned on or off. Anyone know a solution?

Did u tried resetting it from the back?

Are you talking about doing a reset on the external battery by poking a safety clip through the hole? Because I am also having issues related to my external battery.

general
 

try resetting it ,
I think it will be back to normal .

Get back if problem occurs after trying,

How to reset?

I got the same problem!
Have you find a solution yet?

I just bought a used external battery off eBay from a reputable dealer. But, now I'm afraid to install it. I just got my es2 last week and I love it. I'd hate to install the battery and fry the scooter. I've heard that the headlight brake issue can be triggered by installing the battery. Any truth to that? Is it worth the risk?