I use both types of batteries. I like the auto ones better because they are easy. Nothing to push, just draw on it and it does the rest. The drawback is that they have a hole in them so they can sense the suction and supply power when you draw. Juice can work its way in and ruin the battery. Most manuals don't have this problem, as they don't need the hole so most of them are sealed. If you go with auto's, just try not to overfill the carts which can run down into the battery. Also, when you're not using the cig, lay it flat so excess juice doesn't flood the battery. If you get manuals, make sure to ask if they are sealed before ordering.