Lithium cells are among the most dense energy storage chemistries in general use for primary batteries and offer the advantage of very long service life in most applications. The lithium energy discharge curve is also very flat, providing a consistently high voltage throughout the life of the battery. Compared with most other types of batteries, lithium batteries are lighter weight, have a wider operating temperature range (making them excellent for cold-water and ice diving), and have a much longer 10 year shelf life. The hermetically sealed construction of lithium cells means they are very unlikely to leak. Lithium cells are environmentally friendly, offering easy disposal since they do not contain heavy metals found in most batteries. Good news for travelers: All the lithium batteries we sell contain less than 2 grams of equivalent lithium content (ELC) and are not restricted by TSA.