All Looguns now ship with a pack of 4 high-drain AA batteries. We now add these on the assembly line so that they're included with every Loogun as standard.
I wrote a post a while ago that described how some customers were using weak, and/or used, batteries in their devices, and that it leads to them feeling like the device doesn't perform as well as it should. To ensure that this doesn't happen, especially once we move into retail, we now include a free pack of high-drain batteries with every device.
When it comes time to replace your batteries, take a look at the blog post describing the best batteries to use in your Loogun.