Sigelei Mini - mine just ran out of charge. I usually charge it before it runs out, but forgot and carried on using it. Got the message 'check battery'. That has happened once before, so I plugged it in and let it charge.
The only way to see what it's doing seems to be to press the fire button to bring the display up, and it can be seen that the lightning flash (not flashing though) is on the battery level indicator.
Telling when it's charged needs it to be disconnected, and then the button pressed! It doesn't seem to bring up a fully charged message no matter how long I leave it.
So, I put it to charge 20 minutes ago, pressed the button to check, and all I get on the screen is a large battery icon with the non-moving lightning flash on it. I tried disconnecting it but the screen was blank. Just pressed the button again, and still just get the battery icon. As you'd expect, the instructions show nothing of this.
I'll leave it for an hour or so to see what happens, but if it's still blank, I'll put a new battery in it.
Although I prefer USB/mains socket charging, it may be that I'll need a charger to better see what's going on with these batteries, especially with the Sigelei.
What charger should I get - don't mind waiting for one from FT if they're OK from there.