"Battery Maintenance" message on remote

I was riding this morning and early into the ride, around 85% battery life, I noticed that my board was slowing down and on the remote it had a message "Battery Maintenance". I simply turned off the board and remote and everything was fine.
I looked at the new GT manual and I saw no note about this message popping up on the remote.

Does anyone have an idea what this means, and the appropriate steps I should be taking ?

Thanks in advance

 

Interesting - as this was my first ride in the morning and I had it on the normal charger overnight, to balance it.

 

Hi, I had the same problem exactly after full recharging. I went for a ride and had battery maintenance message, it stuck only in Eco mode but then I realised actually you can change the mode Maybe in 5 sec , you need be quick after you turning your board on and then remote then in 5 sec you can change to the faster modes (fast or GT).
I managed to ride nicely 5 km and back home, my plan was (first time) opening the battery cover to see if I could connect to the balance charger and then empty the battery or balance charge.
While I was playing with it I unplugged the batteries main cable and the balance connector and this process took a few minutes, and then I gave up. But when I gave it another try it started without any problem or any error message.
That means the solution is just to unplug the battery cables and leave it a couple of minutes, then plug it back again.
Cheers guys I hope it helps.