How Does a Lithium Battery Work?


A lithium-ion (Li-ion) battery is an advanced battery technology that uses lithium ions as a key component of its electrochemistry. Li-ion batteries can use a number of different materials as electrodes. The most common combination is that of lithium cobalt oxide (cathode) and graphite (anode), which is most commonly found in portable electronic devices such as cellphones and laptops. Other cathode materials include lithium manganese oxide (used in hybrid electric and electric automobiles) and lithium iron phosphate. Li-ion batteries typically use ether (a class of organic compounds) as an electrolyte. *Per UW Study


During a discharge cycle, lithium atoms in the anode are ionized and separated from their electrons. The lithium ions move from the anode and pass through the electrolyte until they reach the cathode, where they recombine with their electrons and electrically neutralize. The lithium ions are small enough to be able to move through a micro-permeable separator between the anode and cathode. In part because of lithium’s small size (third only to hydrogen and helium), Li-ion batteries are capable of having a very high voltage and charge storage per unit mass and unit volume. *Per UW Study

Lithium-ion Cylindrical Cell Anatomy

Graphic provided by the Department of Energy (DOE Site)

What are the different types of Lithium-ion cells?


Lithium-ion Pouch Cell Anatomy

The pouch cell offers a simple, flexible, and lightweight solution to battery design. Some stack pressure is recommended but allowance for swelling must be made. The pouch cells can deliver high load currents but it performs best under light loading conditions and with moderate charging. The pouch cell makes the most efficient use of space and achieves 90–95 percent packaging efficiency, the highest among battery packs. *BU


Lithium-ion Prismatic Cell Anatomy

The modern prismatic cell satisfies the demand for thinner sizes. Wrapped in elegant packages resembling a box of chewing gum or a small chocolate bar, prismatic cells make optimal use of space by using the layered approach. The prismatic cell improves space utilization and allows flexible design and are often used for electric powertrains in hybrid and electric vehicles or power storage systems. *BU


Lithium-ion Cylindrical Cell Anatomy

The cylindrical cell continues to be one of the most widely used packaging styles for primary and secondary batteries. The advantages are ease of manufacture and good mechanical stability. The tubular cylinder can withstand high internal pressures without deforming. The cylindrical cell design has good cycling ability, offers a long calendar life, and is economical, but is heavy and has low packaging density due to space cavities. *BU

What are the advantages of Lithium-ion technology?

Li-ion Longer Life


Lithium-ion technology provides 5-10 years of use compared to 18-36 months for a standard SLA or AGM battery.

Li-ion Faster Charge


Lithium-ion technology offers 25%-50% faster and more efficient charge times compared to a standard SLA or AGM battery.

Li-ion Half the Size


Lithium-ion’s chemistry provides higher energy density compared to standard SLA or AGM batteries resulting in a 50% lighter battery and smaller overall footprint.

Li-ion More Cycles


Lithium-ion technology provides more than 7x times the battery cycles than standard SLA or AGM batteries are capable of providing many years of use.

Li-ion Power


Lithium-ion’s chemistry not only offers more consistent power over the life of the battery compared to a standard SLA or AGM battery, but it also allows more power with each cycle use.

Li-ion Lower Cost


Lithium-ion batteries are a great investment lasting longer and costing less over the life of the battery compared to purchasing several SLA or AGM batteries over a 5-10 year period.

Li-ion Safety


Lithium-ion technology is much safer with no gas emissions or corrosion and the additional protection via a Battery Management System (BMS) compared to a standard SLA or AGM battery.

Li-ion No Maintenance


Lithium-ion requires no maintenance – no periodic discharging, no water to refill, and no corrosion to clean compared to a standard SLA or AGM battery.

Series and Parallel Connections Explained

Series Battery Connection:

MORE POWER: Series connections involve connecting two (2) or more batteries together to increase the voltage (power) of the battery system while maintaining the amp-hour rating. Batteries in-series should have the same voltage and capacity rating to avoid damaging the batteries. This connection is simple, you connect the positive terminal of one battery to the negative of another until the desired voltage is achieved. Keep in mind you need to utilize a charger that matches the in-series system voltage. To maintain proper balancing you should charge each battery individually.

Below you will see an example of two (2) 12v 100Ah batteries wired in-series creating a 24v system but still 100Ah.

Think of this option as adding “horsepower” to a car BUT you still only have a regular-sized gas tank.

With two (2) 100Ah batteries in-series, you have doubled your system’s “horsepower”. You now have more power just for a standard duration.

Parallel Battery Connection:

MORE CAPACITY:  Connecting two (2) or more batteries together in-parallel increases the overall capacity of your system, but your voltage remains the same. The positive terminals are connected together with the proper gauge cables and the negative terminals are connected together with the proper gauge cables until you reach the capacity needed. Unlike a series connection, the in-parallel connection does not increase the normal voltage output, but it will increase the duration of the power. Charging batteries connected in-parallel may require longer charge time.

Below you will see an example of two (2) 12v 100Ah batteries wired in-parallel creating a 12v system with 200Ah’s.

Think of this option as adding a “larger gas tank” to a car BUT you still only have the original horsepower.

With two (2) 100Ah batteries in-parallel, you have doubled your system’s “gas tank”. You can now go farther and last longer!