You can build your own packs by soldering them together, but there is a huge word of caution that should go with it. Batteries such as this are very easy to ruin. If you get the top of the battery cell too hot it will melt the seal of the battery cell which could cause the battery to fail in flight. Trust me, it doesn't take too much heat to melt that cell. A couple of seconds can sometimes be too much. If you're interested in doing this there is a website dedicated to EVERYTHING about RC batteries. You can find it at [link=http://www.rcbatteryclinic.com]R/C Battery Clinic[/link]

Hope this helps

Ken