"Get the lead out." It's an expression used to tell someone to move faster. For cars, accelerating faster results from adding power or cutting weight. “Getting the lead out” of a vehicle’s battery by switching to a Lithium-Ion battery can cut 20- to-40 pounds or more. In addition to weight savings, Lithium-Ion batteries can provide a longer service life that’s up to five times longer than a lead-acid battery. Of course, all these benefits come at a cost. To help determine if the logic of lithium makes sense for your application, we’ll review some battery basics, take a look at the science behind lithium batteries, explore battery testing and then review the specs on some popular Lithium-Ion batteries from three leading manufacturers.

BATTERY BASICS

In a streetcar (and every racecar that uses an alternator), the battery’s primary function is to start the engine. Once the engine is started, the vehicle’s charging system (usually consisting of an alternator with an internal voltage regulator) powers the electronics. Under extreme current demands that exceed the capabilities of the alternator, the battery may serve a secondary purpose as an energy reserve to help power the vehicle electronics. In instances where the charging system of a vehicle fails, the battery’s energy reserve can often power the vehicle electronics long enough to limp home or go the distance to a repair station. Along those same lines, vehicles set up for tailgating parties or car shows (where the electronics are on without the engine running to power the charging system) must choose a battery with the reserve capacity to meet the demands.

THE LITHIUM ADVANTAGE

Lithium-Ion battery technology (more specifically Lithium-Iron ion) offers some performance advantages over conventional lead-acid batteries. First, lithium-ion batteries feature an energy density that’s roughly three times the value found in flooded or AGM lead-acid batteries. Second, lithium-ion batteries charge faster than conventional lead-acid batteries, so it doesn’t take long to restore the energy used up during the starting of the vehicle. They also charge more efficiently and this means less load on your alternator. Less load on the alternator results in more power at the flywheel when the battery is being charged. Third, lithium-ion batteries offer better deep-cycle performance. Traditional lead-acid batteries designed for automotive use put little emphasis on deep-cycle performance. As a result, severely draining these batteries below 70-percent of their capacity can lead to degraded performance and damage. With lithium-ion batteries, the deep cycle capabilities are three times that of a conventional lead-acid battery. Finally, Lithium-ion batteries are currently believed to be more friendly to the environment than lead-acid batteries.

THE LITHIUM LIABILITY

Sounds great, but there are a few catches. First and foremost, one drawback to Lithium-ion battery technology is price. As a new and continually developing technology, the cost to manufacture a proper Lithium-ion battery for automotive and motorsports use is still substantially higher than even the premium AGM lead-acid batteries. On average, expect to pay 3-to-10 times more for Lithium-ion technology. Second, Lithium-ion batteries are also warm blooded as they deliver peak performance at room temperatures and slightly above. Using your Lithium-ion battery in below freezing temperatures will reduce the life expectancy of the battery. Third, Lithium-ion batteries do not self-balance between cells and can be damaged by overcharging or overdischarging. When left unchecked these issues can lead to degraded performance and shortened battery service life.