18650 vs. 21700 vs. 20700 Batteries: What’s Best for Your Vape Mod?

If you’re in the market for a new vape mod, you’re going to need to choose between a device with a built-in battery and one with a removable battery – and if you’re shopping for a removable battery mod, that decision isn’t as simple as it once was. In the past, buying a vape mod with a removable battery always meant that you’d be using 18650 batteries because those were the most popular batteries for virtually all consumer devices.