What do all these NiCd, NiMh and Lithium Ion mean?

     NiCd is Nickel Cadmium, NiMh is Nickel Metal Hydride. They are the 3 main kinds of batteries in the market these days. Metal Cadmium is the most common type of battery cell, and usually the cheapest. However, NiCd batteries have ""memory effect"", which require them to be fully-discharged before recharging. NiMh batteries, on the other hand, have negligible ""memory effect"", and are more environmentally friendly. They have shorter life cycles in general. However, lithium ion batteries are gaining in popularity due to their slim dimensions, high energy density, and reasonably long battery life. ?These qualities have made them a favorite among cellular phone owners. Lithium Ion battery cell?has no ""memory effect".