Lithium Ion (Li-Ion) battery technology is one of the fastest-growing trends in the tool community, and certainly for good reason. Lithium-Ion batteries have the best energy-to-weight ratio, meaning they pack the most power with the smallest amount of bulk. They also experience no memory effect or, lazy battery effect. This occurs when a battery can no longer accept a maximum charge for having been repeatedly recharged without being fully used (a common symptom of Nickel Cadmium (NiCad) batteries). Li-Ion batteries, conversely, have absolutely no memory and can continually accept a maximum charge. Additionally, Lithium Ion batteries have a very slow rate of charge loss while the battery is disengaged.

What is the difference between Lithium Batteries and Lithium Ion Batteries?

The difference is in the chemistry; a Lithium battery is a disposable power source composed of lithium metal compounds - the key word, here, being disposable; Lithium batteries can not be recharged. Lithium Ion batteries, on the other hand, are intercalated, meaning the lithium ion inside the battery moves between two internal electrodes. This movement, or reversibility of the lithium ion accounts for the battery's rechargeability.

What are the benefits of Lithium Ion Technology?

-- Lithium Ion batteries hold a lot of power and are surprisingly light-weight, especially with consideration to other rechargeable batteries.
-- Li-Ion batteries combine single cell technology with a greater energy reservoir than Nickel Metal Hydride and Nickel Cadmium batteries. They store more power for their size than both NiCad and NiMH.
-- Li-Ion batteries hold their charge for significantly longer than other comparable batteries and provide steady power until that charge is completely gone. Other batteries gradually and consistently lose power as you work. Li-Ion batteries stay strong until the last push.

Are there disadvantages to using Lithium-Ion Batteries?

The disadvantages of using Li-Ion battery technology are generally few and far between, and technological advancements are making them even less so. Manufacturers have recently improved the Lithium-Ion recipe to reveal a more reliable battery. Still, every giant has its weaknesses:

-- Li-Ion batteries are sensitive to intense hot and cold temperatures. In extreme temperature conditions, the battery will degrade more quickly.
-- Li-Ion batteries degrade regardless frequency of use.
-- The Li-Ion battery's built-in computer chip tells the battery to refuse a charge once the batteries power falls below a certain point. If this occurs, the battery is beyond repair.

Although these defects are more applicable to the older Lithium Ion batteries, the possibility of seeing these problems is still worth noting. Fortunately, these said defects are fairly rare and easily avoided.

-- Store Li-Ion batteries (and other batteries as well) in a cool, dry place.
-- Use your Li-Ion batteries often.
-- Be certain Li-Ion batteries have a full charge before storing them, and pull them out every so often to use and recharge. Watch the batteries power level to be sure it doesn't fall below the charge limit.

General Li-Ion Battery Tips:

-- On occasion Lithium-Ion batteries require more than one charge (sometimes 2 to even 10) to accept a full charge. The first time you charge your battery, leave it to charge overnight. This ensures you'll have maximum power for your first use.
-- To maintain proper balance in your battery, leave it to charge overnight about once per week for the life of the battery.
-- When buying a new Lithium Ion battery, make certain you are buying a fresh one. There's a chance a battery has been degrading on the shelves of manufacturers and distributor's so be certain you are buying a new one. Most manufacturers provide a date code on the battery or packaging. Check dates before you purchase, and be confident you are getting a fresh, high-performance battery.