With technology constantly evolving, an optimal battery has become a must for all modern devices.

While there are different kinds of batteries available, you need to understand the specifications of each of them to determine which battery is best for your bike’s overall performance.

Two of the most popular options people look at are Lithium-ion batteries and traditional AGM batteries. 

Let's drill down into the pros and cons of AGM vs Lithium.

What happens inside a battery?

Batteries contain electrodes that conduct electricity and an electrolyte (containing charged particles) that converts chemical energy into electrical energy.

So, it is the battery that ensures the smooth functioning of the equipment by feeding an uninterrupted power supply.

And, most importantly, the battery cranks the engine, hopefully without any hiccups.

Let’s take a look at two of the most common types of batteries used these days.

What is an AGM battery?

One of the most widely used battery types, the AGM or ‘Absorbed Glass Mat’ battery was introduced as the ‘dry’ successor to the conventional flooded battery.

The AGM battery contains a distinct glass mat separator that wicks the electrolyte solution between the battery plates. This helps to store the electrolyte in a ‘suspended’ or ‘dry’ state, rather than sloshing around in free liquid form.

As the battery operates, the electrolyte is transferred from the glass mat to the battery plates as required.

Therefore, the AGM battery is often called the maintenance free battery, as it does not require any topping up with water.

Moreover, thanks to its low resistance, the AGM battery can handle higher temperatures; as a result, their self-discharge rate is as slow as 3% per month.

What is a Lithium Ion battery?

Lithium-ion batteries are the family of rechargeable batteries that have gained incredible popularity in recent years. Specifically the LiFePo4 or Lithium Phosphate type of lithium for it's fire safety and cycles

They are more efficient, 1/3 the weight and more compact.

A LIB consists of a lithium positive electrode and a carbon negative electrode, whereas its electrolyte consists of lithium ions in an organic solvent.

The ions move towards the positively charged electrode while discharging, and the process reverses when the battery is being charged.

AGM vs Lithium-Ion Batteries

The following differences explain the various advantages and disadvantages of AGM and lithium-ion batteries.

 

Advantages

  • AGM batteries are cheaper than Lithium batteries.
  • AGM batteries are more environmentally friendly and recyclable.

Disadvantages

  • AGM batteries have a shorter lifespan than other types of batteries.
  • They tend to self-discharge faster than other types of batteries.
  • They are heavy.
  • They are not suitable for all applications.

Size of the battery

Lead acid AGM batteries are bulky and large in comparison to lithium-ion batteries. To match the capacity of a compact lithium-ion battery a lead-acid battery would need to be around 3 times the size of its counterpart.

Therefore, lithium-ion batteries are more compact and more energy efficient than lead-acid AGM batteries.

Life cycle

Lithium-ion batteries have an extremely longer life cycle than AGM lead-acid batteries. The life cycle of a battery depends upon certain factors including discharge rate, depth of discharge (DoD) and temperature. AGM batteries are more sensitive to these factors than lithium-ion batteries.

Average life of AGM/SLA batteries is about 3-4 years on average

Average life of good LiFePo4 is about 12-15 years.

Temperature

In high temperatures in excess of 92 degrees Fahrenheit, the life cycle of the AGM batteries dips to half of what it was at more moderate temperatures. But the more resilient lithium-ion battery holds up and remains stable until temperatures exceed 120 degrees Fahrenheit.

While the performance of both battery types declines in persistent cold weather, the lead-acid battery loses its capacity more rapidly than the lithium-ion battery.  

At freezing it's important to have a BMS on a lithium battery that prevents charging as lithium is damaged by charging below 32 degrees.

Initial Cost

The initial cost of lead-acid AGM batteries is low when compared to the more lithium-ion batteries. If you are looking for a battery on a tighter budget then AGM Batteries may be attractive for regions milder in temperature.

Lithium-ion batteries have a high initial cost but can endure more robust conditions, and lifetime easily make up for the cost difference.

Maintenance

Lead acid AGM batteries come packed as kits and require little maintenance. For a two-wheeler being used regularly, all you need is to keep the battery terminals clean. But if the two-wheeler is rarely used, the battery tends to self-discharge and the effective capacity of the battery reduces.

Lithium-ion batteries, on the other hand, are not very prone to self-discharge as they can remain active over a long idle period. But these batteries are charger specific and require to be charging with their specific charger compatible for the purpose.

AGM vs Lithium final thoughts

Batteries play a crucial role in our daily lives. While both AGM and the lithium-ion batteries have their own pros and cons, the suitability of each type of battery depends upon the various factors explained above.

Both batteries have their advantages and disadvantages and it's up to you on what will suite you best for your bike.