Battle of Battery Chemistries: Lithium-Ion Versus Ni-MH

Lithium IonUnderstanding all of the different battery chemistries that exist and what the pros and cons are of each can be a daunting task for many. In regards to laptop batteries, however, there are two that everyone should become familiar with as they are far and away the most commonly used by laptop manufacturers: Nickel Metal Hydride (Ni-MH) and Lithium Ion (Li-Ion).

Lithium Ion (Li-Ion)

Li-Ion has emerged and firmly established itself as the chemistry of choice for the overwhelming majority of laptop manufacturers worldwide. This is largely because they offer a higher energy density than any other chemistry, which creates highly-desired benefits such as longer lifespans and higher per charge capacity. Li-Ion batteries also experience lower levels of self-discharging compared to Ni-MH and other chemistries.

Lithium-Ion batteries move electrons back and forth from Lithium Oxide to Graphite. Li-Ion cells each carry 3.6V, with 6 to 12 typically packed inside each laptop battery. Because the electrochemical reaction in Li-Ion batteries needs to be monitored more closely than that of other batteries, Li-Ion laptop batteries come with a microprocessor that controls the charge and discharge rate, as well as monitors the temperature and capacity of the battery. While this initially caused Lithium-Ion laptop batteries to be a bit more costly, battery manufacturers have developed inexpensive and effective methods of ensuring that they would function properly.

So the next time you need to buy a new battery for your laptop, arm yourself with some key bits of knowledge before making your purchase. Doing so will go a long way in ensuring you’re getting the most for your money.

Nickel Metal Hydride (Ni-MH)

Before Lithium Ion batteries became the ‘battery du jour’ for laptop manufacturers around the world, Nickel Metal Hydride (Ni-MH) was the chemistry most commonly used.

In a Ni-MH laptop battery, the electrical current moves cells from Nickel oxy-hydroxide to a metal alloy, with each cell carrying 1.2 Volts. Before Ni-MH became a preferred battery chemistry of laptop manufacturers, Nickel Cadmium (Ni-Cd) was being used in the majority of laptop batteries. Ni-MH was seen as an improvement because of its larger charge capacity and non-toxicity. However, Ni-MH batteries will typically lose about 10% of their capacity within 24 hours of being charged and have a shorter lifespan than today’s Lithium Ion batteries.