As a child growing up, I was familiar with two types of batteries: the D size that was used in flashlights and the AA that was used for everything else. In today's society, technology is constantly changing and batteries are now becoming more and more advanced. We have seen the emergence of rechargeable batteries, lithium batteries, nickel cadmium batteries, nickel metal hydride batteries, lithium ion batteries, cordless power tool batteries, medical equipment batteries, batteries for communications, electronics, video, security devices, power tools, home appliances, battery powered toys, memory back-up and mobility. .
             Rechargeable batteries can only be re-charged so many times and the need for electricity is diminishing as batteries are becoming more powerful. They are now seen as a chokepoint in the use of alternative energy. Three sources of energy that I will focus on are Nickel Metal-Hydride, the new and improved Lithium Ion and Fuel Cells.
             Nickel Metal-Hydride (NiMH) batteries were introduced in the early 1990's as the new high-tech replacement over older chemistries like Nickel Cadmium (NiCd). Although they may have a very slight memory effect, NiMH batteries are much more reliable than previous chemistries. Compared to a NiCd battery of equal size, a NiMh battery will run for 30-40% longer on each charge. NiMH batteries can also be recharged 60% in just 15 minutes. Longer Nickel Metal Hydride batteries stay powered up longer, have no memory to drain and are environmentally friendly: mercury-free. Most new laptop computers and cordless phones are equipped with these cells now. One disadvantage of this battery is that its very sensitive to overcharging and complete discharging. The self discharge rate is very high so it's not a good idea to leave them sitting around for even a couple of weeks.
             The introduction of lithium-ion technology represented a breakthrough in safety from the old lithium metal batteries. Lit...