| Three main types of rechargeable batteries | | | | also higher capacity than NiCad and are said |
| are used in newer technology hand held | | | | not to suffer from the "memory-effect" quite |
| devices. Scientists are constantly trying to | | | | as much. Following the proper steps for |
| develop batteries with better technologies | | | | charging and discharging in NiMH batteries is |
| that make them faster, more powerful, and | | | | very important. NiMh batteries need smart |
| more lightweight. In the past, the only type | | | | chargers which prevent them from |
| of rechargeable battery available was a | | | | over-charging. It is also important that they |
| lead-acid battery, which contains liquid and | | | | are not run flat in a portable device, which |
| must be kept ventilated in an upright | | | | creates reverse charging, which can |
| position. Though still used in autos and | | | | completely damage the battery. Most devices |
| motorcycles, scientists have developed | | | | detect safe discharge voltage and shut down |
| gel-batteries, where the liquid is semi-solid | | | | automatically. In this case, NiMH batteries |
| and will not spill. These batteries, most | | | | are much more effective in high drainage |
| commonly used in new had held devices are | | | | devices like digital cameras, while NiCad |
| nickel-cadmium (NiCad), nickel metal-hydride | | | | batteries are more effective in devices with |
| (NiMH), and the newest, Lithium Ion (Li-Ion) | | | | a fast discharge rate such as power tools. |
| batteries. | | | | NiMH batteries are also used in hybrid cars. |
| | | | |
| Nickel Cadmium, or NiCad batteries are the | | | | The newest and most powerful of all |
| least expensive of the three types, because | | | | rechargeable battery types is the Lithium Ion |
| it has the least power. They are primarily | | | | battery. When compared to NiCad and NiMh |
| used in portable phones, power tools, and | | | | batteries, Li-Ion batteries have the highest |
| other hand held devices. They are more | | | | voltage density and the lowest self-discharge |
| practical than lead-acid batteries because of | | | | rate. It is the smallest and most |
| their increased power and light weight. They | | | | light-weight of all the batteries, but all |
| also have an advantage over alkaline | | | | the advantages make it much more expensive as |
| batteries which are not usually rechargeable. | | | | well. New Li-Ion batteries are said to charge |
| NiCad are said to be the number one sufferer | | | | 10 times faster than NiMH or NiCad batteries, |
| of the "memory effect" which in fact is | | | | and does so in a fraction of the time. Li-Ion |
| really a lazy battery effect, where the | | | | are extremely susceptible to high |
| battery discharges quickly after being fully | | | | temperatures which can great shorten their |
| charged. A NiCad battery only lasts 1000 full | | | | lifetime. Extremely high temperatures can |
| cycles, so eventually they need to be | | | | also cause a Li-Ion battery to explode. |
| replaced. | | | | |
| | | | Different types of batteries have their |
| NiMh batteries are next of the podium for | | | | advantages and disadvantages. While some |
| newer, more powerful batteries. Though | | | | offer more convenience and higher capacity, |
| similar to the NiCad batteries, NiMh | | | | there are still many limitations facing the |
| batteries do not contain toxic cadmium, so | | | | development of batteries. However, battery |
| they are considered more of an | | | | technology is improving everyday to help |
| environmentally-friendly battery. They are | | | | portable devices last longer. |