Manual eGo batteries are sealed. You are not going to ruin your ego. You can burn up your atomizer if it is dry. I add a drop or two directly into the atomizer before using cartridges. Most eGo kits come with pre-filled carts of some kind. You can take the filler out and rinse out the pre-filled juice, dry it, put it back in and use a different juice. Direct dripping is excellent using at home. I didn't think I'd get into it, but it's about all I do at home now. Dripping has generally better flavor and you can switch easily between juices. I found this forum a great way to lower the learning curve and read about all the options available.