To charge an Elf Bar Lost Mary OS5000, you'll need a Type C USB charging cable. These are easy to purchase and affordable. When the LED colors display of your OS5000 goes red, that indicates a low battery.
Simply plug your charging cable into the port of the device and leave it to charge for thirty minutes. Once it's charged, it should have a green light when you switch it back on. If it doesn’t then it’s recommended you troubleshoot it and if it can’t be charged, dispose of it.