What is the difference between Ni-Cd, Ni-MH, and Li-ion?

Li-ion (Lithium Ion). This is one of the newest cell types available. It is also the lightest battery type currently available on a commercial basis and can provide more power than the other main cell types. There are no known problems of memory effect with this battery type and it is the easiest battery type to care for. The downside of this battery is that it has the highest engineering costs and therefore the price is usually considerably higher than other cell types.

Ni-MH (Nickel Metal Hydride). This cell type is the most common cell type currently available for laptop computers (although Li-ion is rapidly becoming the most popular). This battery type is relatively cheap to manufacture and therefore tends to be cheaper than Li-ion. This cell type is prone to memory effect, so it is important to take good care of your Ni-MH battery to ensure that you obtain the best runtimes.

Ni-Cd (Nickel Cadmium). This is one of the oldest cell types and is generally only found in older laptops. The main pro for this cell type is its ability to handle higher loads, and therefore is more commonly found in portable power tools or devices that need a lot of power to work efficiently. The main downside of this cell type is that it is notorious for suffering from memory effect, so good care must be taken with this battery type to ensure most effective use of battery.