2012 TE250, chugging then dying, no electrical power

Having some kinda electrical issue with a 2012 TE250. This issue started out rare and is becoming more common for us. Turn key and we get no electrical power, no dash lights, starter won't work. Nothing. Today my wife was riding along and the bike started to chug and then it just died, no power again. Though pushing the start/stop button, turning the key, and shifting gears I eventually got the dash on again, but then it would go out when I tried to start or the fuel pump tried to prime. The was a number displayed on the dash at times 108. Eventually I did get it to start and let it idle awhile, then it started to chug and died again with no electrical. At this point we were done for the day, once again I got it started and we were able to get it home. Now in the garage working the key and start/stop button it will sometimes be fine and sometimes have no power. I read something about some faulty start/stop buttons but could this be the source of no power at all? Seems the key should control the power and the starter button should only control the fuel pump? I also wondered if possibly her battery was going bad but I'd think once it was started the battery wouldn't matter. When I tested the battery it showed 12.8v so that should be fine. Can anyone help me?

If it is the original battery and the bike has spent a long time sitting not on a charger then I would consider a new battery.

Also, I'd spend some time cleaning and greasing the connections in the wiring harness.

The TE has a lot of wires and accessories for a street legal bike and they are delicate. Look for wiring damage also.

You are right about the key. It controls the lights and IGN. The kill button controls the IGN and fuel pump.
When it dies, does the headlight go out also? If not, look at the kill button. Maybe you dropped the bike in the mud on the right handlebar and submerged it?

also check the main fuse located on the starter solenoid - could be loose, it powers up the entire bike. I had this blow when I was 20hr drive away from home. had to strip the plastics to find it.

May be worth checking the other fuses also. I was having similar issues and once I replaced all the fuses I had no more problems. They did look fine but were not!