Skip the LiPo and just pick up a new NiMh or NiCd battery pack and test it with that. The cost of a LiPo would be more than the NiCd or NiMh just to try it to see if it works or not. If it works, then just stick with the NiCd or NiMh pack.

The LiPo will require a regulator to set the power level to approx. 4.8 volts (5 volts would be fine) and the cost begins to build up. There is a post with a thread about using LiPo packs to replace 4.8 volt NiMh or NiCd packs in smaller RC aircraft.

You can get your NiCd pack either at your local hobby shop, Tower Hobbies, or RadicalRC.com (or anywhere else that you can get a dependable and reliable battery pack). Just be careful and don't try to build one yourself if you intend to fly with it... soldering packs together can cause serious problems with the packs if you are not very familiar with soldering battery packs in series.

Hope this helps.

CGr