The charger indicates the battery is charged. I connect it to the tank and the button gives those multiple blinks indicating it is discharged. I tried it on the USB port, and again, there is a full charge indication from the charger, but not when set up and pushing the button. I tried this with both batteries; same result. Now, when I switched to the backup tank, everything works. Clearly, there is something wrong with one tank (or whatever it's called) but I can't imagine where the problem is. The set up is only about a week old, if that matters. Has anyone even seen something like this? I'd rather a cure than a shared experience, but I'll take whatever I can get.