Mine are all fine, you sure you're not doing something silly with them like using them on crazy high current draw stuff or getting them wet or something?
Most odd. I have three Anker. I've used one of them a shitload. All my races, most training rides over say 7hrs and no issues with it or the other two (one smaller lipstick, one big double usb one).
How are you charging them? Tried plugging into a PC?
Mine are all fine, you sure you're not doing something silly with them like using them on crazy high current draw stuff or getting them wet or something?