The Think Vape Asteroid Pod Kit sports an ultra portable form factor, making it incredibly easy to take with you. Not to mention, with a size like this, it's perfect for stealth vaping. It does have an internal 420mAh battery, which can be charged via its micro USB port. There's a battery light indicator as well, notifying you of the current battery state. The Asteroid does have a constant voltage output of 3.7v, so you'll get a consistent vape experience from start to finish.