Blu batteries are weenie. They ate just too teeny to power anything for very long. I keep mine in my car as an emergency back-up.
However- don't despair. The atties and cartos are fabulous and can be used on bigger batts (if you are ready to move up). The blu atty is similar to the 306. It will fit with anything that has a 510 fitting (ie: 510, ego, volcano, etc). You can easily purchase some parts that will fit what you have now, and save your little batts for back-ups.
*just one word of caution... Do NOT mix up your chargers. I suggest labelling them. The polarities are reversed, so you will fry your batts if you mix them up.
Sent from the beach