The lithium-ion (Li-ion) battery is touted as the battery of choice for the green world. This means that it is considered to be the greenest of the battery choices, and this has been the case for some time. While it may have many disadvantages and flaws, it is only fair to mention that almost anything can have problems if not used, stored, or handled correctly. There are those who oppose anything that is contrary to what they are accustomed to using, or what they themselves believe in. All facts must be taken into consideration to make an informed decision about the Li-ion battery.
The advantages are:
The battery is much lighter than other rechargeable batteries of equal size. The composition makes it capable of creating custom battery packs and packing far more power into a smaller. The closest competitor is the nickel-metal hydride (NiMH) battery which generates only about half the corresponding power. For the Li-ion battery, the power output is 150 watt hours per kilogram. For the NiMH battery the ratio is 60 to 100 watt hours per kilogram (100 is often listed, but not typical) for the same weight.
Compared to other battery types, the battery will hold its charge-losing only about 5% per month. The NiMH battery loses up to four times as much each month.
It is not necessary to completely discharge a Li-ion battery before recharging it. Complete discharge will kill the Li-ion battery as mentioned previously. The disadvantages of the Li-ion battery are:
The Li-ion battery starts to die as soon as it is shipped. Even if it is never pulled from its package and used, the -Li-ion battery has a total maximum life expectancy of three years at this point. Once it is packed and shipped, the Li-ion battery works toward its own end. This is true whether it is idle, in full use, or in cyclical demand.
Heat decreases the life expectancy. The higher the temperature, the faster the battery loses its charge.
Complete discharge will kill a Li-ion battery. Other batteries can be charged and discharged completely without causing a problem, but complete discharge will destroy the Li-ion battery completely.
They are expensive. The Li-ion battery pack requires an on-board computer to work properly. This fact makes them very expensive indeed.
The Li-ion battery pack carries a small risk of fire in the event of failure.