My Merida eOne Sixty with ep8 motor has been sat in my garage for almost 5 weeks (yes, I know, don't judge me!

) The main battery was at just under 60% charge when I left it. I went to check on the bike yesterday and pressed the power-on button. The display came on for a second then went black. I tried again, same thing. That has never happened before to either of my previous Shimano motors, but then I've never left them standing for so long before either. I had read on here that there is a re-chargeable battery in the power-on switch that can go flat if left for too long. I had also read on here that if you remove a rubber plug on the top of the down tune and poke through with a narrow screwdriver you can switch on the battery. Am I correct with both of those?
Anyway, it was cold and I'd had a brew so instead I put the bike on charge for 30 mins. It was in the hope that it might recharge the power-on battery and/or reset anything else that may have gone wrong.
Whatever it was , it worked! All is now well.
So, file that away for whenever it happens to you.