I'm a total newbie. I just got my 510s from Innovapor. I got 5 manual batteries and two of the single-piece USB chargers, among other things. When I plug the charger into the USB port without a battery connected, I get a solid blue light on the charger. When I connect a battery to the charger I still get a solid blue light on the charger. It's the same thing with all 5 batteries and both chargers, so they must be working correctly, but does that mean the batteries are already charged or not? If I vape with any of the batteries, the LED on the battery turns on solid, but then starts blinking after 2 or 3 seconds. Does that blinking mean the battery is low or what? I do get good vapor, but I'm afraid of ruining my batteries or atomizers by running my batteries too low. Help!