Get a Turnigy Accucell 6 for charging, that will cover all your charging needs up to 6 cells and will do NiCad, NiMh, LA, as well.

You can add an extra safety feature by using a lithium cut off.

Best way to avoid accidents though is over spec the battery. Conker had a 4000mAh lipo for its drive. We used it in 3 fights and only drew about 1.5-2A each time so no danger of draining the cells to dangerous levels.

Edit: Darn you PJ & Dave! :-)