Rechargeable Battery - Lithium Batteries - Advantages And Limitations Of This Power Source

Lithium batteries are primary batteries that have lithium metal or lithium compounds as an anode.

Depending on the design and chemical compounds used, these batteries can produce voltages from 1.5 V to about 3 V, twice the voltage of an ordinary zinc-carbon or alkaline cell.

These are used in many portable consumer electronic devices, and are widely used in industry. The term "lithium batteries" refers to a family of different chemistries, comprising many types of cathodes and electrolytes.

The most common type of these used in consumer applications uses metallic lithium as anode and manganese dioxide as cathode, with a salt of lithium dissolved in an organic solvent.

These offer high energy density, high capacity and long cycle life in the most common, lightweight sizes - with no memory effect. These cells, which operate over a wide temperature range, are ideal for many portable electronic devices - including rugged military equipment. This chemistry is superior to nickel and lead-based chemistries and the applications are growing as a result.

Lithium-Ions (sometimes rendered Li-Ion) are the pinnacle of camcorder technology. They offer quick charge times, long life, steady discharge characteristics, low weight and small size.

These offers about 40% more charge capacity than a NiCd battery of similar size and weight and can be fully charged in less than half the time. These are also the most expensive type of camcorder power cells available on the market today.

Unlike the other technologies, you can keep your Li-Ions fully charged: go ahead and top off a 90% charge back up to 100%. Otherwise, care and handling is the same as you are accustomed to. Keep them cool, dry and safe from shock. Be sure to recycle them when they're ready to be discarded.

How to Prolong Lifespan:

Research is focusing heavily on these new chemistries, so much so that one could presume that all portable devices will be powered with these advanced technologies in the future. In many ways, this chemistry is superior to nickel and lead-based chemistries and the applications for this newer advancement are growing as a result.

Lithium batteries provide 300-500 discharge/charge cycles. It prefers a partial rather than a full discharge. Frequent full discharges should be avoided when possible. Instead, charge more often or use a larger battery. There is no concern of memory when applying unscheduled charges.

These are memory-free and in use typically lasts between 2-3 years. The capacity loss manifests itself in increased internal resistance caused by oxidation.

Eventually, the cell resistance reaches a point where the pack can no longer deliver the stored energy although it may still have ample charge.

An aged battery can be kept longer in applications that draw low current as opposed to a function that demands heavy loads. The speed by which lithium-ion ages are governed by temperature and state-of-charge. Not only is it better to charge these at a slower charge rate, high discharge rates also contribute the extra wear and tear.

This is a low maintenance battery, an advantage that most other chemistries cannot claim. There is no memory and no scheduled cycling is required to prolong the battery's life.

In addition, the self-discharge is less than half compared to nickel-cadmium, making Li-Ions well suited for modern fuel gauge applications. These cells cause little harm when disposed.

Advantages:

* High energy density - potential for yet higher capacities.
* Does not need prolonged priming when new. One regular charge is all that's needed.
* Relatively low self-discharge - self-discharge is less than half that of nickel-based batteries.
* Low Maintenance - no periodic discharge is needed; there is no memory.
* Specialty cells can provide very high current to applications such as power tools.

Limitations:

* Requires protection circuit to maintain voltage and current within safe limits.
* Subject to aging, even if not in use - storage in a cool place at 40% charge reduces the aging effect.
* Transportation restrictions - shipment of larger quantities may be subject to regulatory control. This restriction does not apply to personal carry-on batteries.
* Expensive to manufacture - about 40 percent higher in cost than nickel-cadmium.
* Not fully mature - metals and chemicals are changing on a continuing basis.