The lithium-ion motorcycle battery is the hot topic these days. Although relatively new to the motorcycle industry, many devices with rechargeable power source have been using lithium-ion batteries. Chances are, you currently reading this article with one such device, namely a mobile phone or laptop.

Lithium-ion batteries provide many more benefits than the age-old lead-acid battery as we will see.

Where does lithium come from?

Lithium (‘L’ on the periodic table) is a naturally occurring element. It is in fact, the lightest metal with a low density. Because of its low density, you can cut it with a knife. 

This alkali metal was discovered by a Swedish scientist just over a century ago but it has become one of the most essential elements in the last 30 years or so due to the exponential advances and growth of consumer electronics, such as the smartphone and electric vehicles.

How does it work?

The lithium-ion battery uses the same operating principles as other rechargeable batteries: Electrical charge travels through an external wire between the electrodes of the battery. Inside the battery, positively charged lithium-ions move through the electrolyte circuit from the negative electrode (anode) to the positive electrode (cathode). Recharging reverses this flow.

But while the cells of a lead-acid battery are exposed, each cell in a lithium-ion battery is fully enclosed to include the different parts and chemicals. For example, a lithium iron phosphate (LFP) cell combine an iron phosphate positive electrode with a carbon negative electrode. If one cell produces 3.3V, four of these cells combine to produce a 13.2V motorcycle battery.

Battery structure and features

The electrodes of the cells are connected to one “collector.” In turn, the collector leads to the external positive or negative terminals, ready to be attached to the motorcycle’s battery cables.

A Battery Management System (BMS) is a must in a lithium-ion battery and Dynavolt lithium-ion batteries feature the BMS. It ensures that all the cells have the same state of charge – meaning each cell has the same charge. This way, the battery lasts longer because you do not get one weak or dead cell. Additionally, the BMS it manages the safe operation of the battery by stopping it from getting too hot. It also regulates the charge that enters the battery, shutting the flow off if there's an electrical surge. Additionally, it stops the voltage and capacity from dropping too low.

Low-quality lithium-ion batteries may feature the BMS, as well, but they may not be programmed thoroughly, or some may not have it at all.

Benefits of using a lithium-ion battery

1. High-rate discharge at consistent capacity

A lithium-ion battery provides high power when called for at a consistent rate. In other words, you have the same power for longer. Conversely, a lead-acid battery’s power drops off considerably over time.

2. Faster charging

A lithium-ion battery typically takes only 2 hours to charge fully, while a lead-acid battery takes up to 10 hours. Imagine if electric vehicles use lead-acid batteries!

For example, a typical motorcycle battery weighs 2.2kg. The equivalent lithium-ion battery weighs only 650g. In other words, a lithium-ion battery has more energy density.

A Dynavolt lithium-ion motorcycle battery lasts up to 5,000 charge cycles, compared to just 1,000 for the lead-acid battery.

A charge cycle is described as the battery being discharged from 100% down to 0%, then charged back up. But it is not as straightforward as that. A good illustration is your phone’s battery: Say you used your phone from fully charged to 35% balance (65% used) and recharge it for the night. The next day, you use another 65%. Of that 65%, 35% completes one charge cycle.

The  lithium-ion battery with 50Ah (Ampere-hour) capacity produces 25,000Ah, while a lead-acid battery with 100Ah capacity produces only 5,000Ah.

The lithium-ion battery produces 96% output with 4% of heat loss, while a lead-acid battery puts out 85% power with 15% heat loss.

A Dynavolt battery at 50% capacity can still start the engine due to its high platform voltage.

The lithium-ion battery can hold its capacity for longer periods of time after being activated because there is no sulphation. By comparison, a lead-acid battery’s plates will begin to sulphate (from the sulphuric acid) and produce lesser power over time.

A good lithium-ion battery such as Dynavolt's will lose 1% of its charge in 45 days, whereas a lead-acid battery will lose 1% per day if it is not charged.

As mentioned above, the lead-acid battery uses sulphuric acid as an electrolyte. Thus, it can leak if the casing is damaged, say in a heavy crash or abuse (overcharging among others). Also, charging a lead-acid battery produces hydrogen which is highly flammable when mixed with the oxygen in the air. This is why you are advised to charge a battery in a well-ventilated area or outdoors. This writer usually removes the lead-acid batteries from his vehicles to charge them!

On the other hand, lithium-ion batteries do not use liquid electrolyte and sulphuric acid. Besides that, each cell is individually sealed and finally sealed again in a tough casing. The absence of emissions means you can charge it anywhere.

Sulphation and discharging in a lead-acid battery accelerates with increase in air temperature. Thus, the best place to store it is in a cool environment. Sellers need to store them in air-conditioned rooms. So, if you bought a lead-acid battery from a seller who stored in a hot and humid condition, chances are the battery will not last. A lithium-ion battery is not so sensitive to ambient heat, except for extremely cold conditions.