One of my battery packs on my delta tool kit died so I had to get a replacement battery. An outift on Ebay is charging about for a rebuild so I decided to do a LiPo conversion. I have the LiPo chargers for my RC stuff so all I had to do was get some batteries. I made sure the 2200maH lipo would fit in the pack then all I had to do was make the elelctrical connecitons. So I have an upgraded pack from 1500mah 18v to 2200mah 22V! And the pack is about half the weight too.