Understanding Motorcycle Batteries: A Practical Guide

Decoding the language of battery marketing can be as challenging as navigating through an Ice Age or trying to solve global warming.

This guide aims to demystify the world of 12-volt motorcycle batteries, each containing nine amp hours of energy but with unique features and specifications. We explore four types of batteries: conventional, Absorbent Glass Mat (AGM), gel, and lithium.

Conventional Battery: The Traditional Option

A Glimpse into History

The conventional motorcycle battery utilizes a method over 150 years old. Involving the process of flooding lead plates with acid is a cost-effective solution, available for around $45, including sulfuric juice.

The Pros and Cons

Despite its affordability, it is hefty, weighing around 3153 grams. Despite its weight, it’s a reliable power source for your motorcycle but requires periodic maintenance and careful handling due to its sulfuric acid content.

Absorbent Glass Mat (AGM) Battery: The Sealed Powerhouse

A Step Up in Technology

For an additional $15, you can opt for an AGM battery. This battery operates on the same fundamental principle as a conventional one, but the acid is absorbed in spongy fiberglass sheets between the electrodes.

This feature allows for shipping with the acid sealed inside, eliminating potential hazards and enhancing its durability during crashes.

The Plus Side

Apart from being safer, the AGM battery weighs less than its conventional counterpart, coming in at 2960 grams. However, it demands a higher price of $130.

Gel Battery: The Heat Resistant Choice

Advanced Spill-Proof Technology

For a slightly higher price, BikeMaster offers a gel battery that incorporates silica into the design to gelatinize the acid, making it spill-proof.

This battery does not require a fiberglass mat like an AGM, making it cooler in hot weather, although slightly heavier at 3025 grams.

Lithium Battery: The High-End Option

Breaking Away from Conventional Chemistry

The lithium battery, priced at $150, is the only contestant to abandon lead-acid chemistry completely. Provided by Shorai, it uses lithium iron phosphate, making it five times lighter than conventional batteries.

Weighing a mere 609 grams and half the size, it offers the unique feature of being mountable in any direction, including upside down.

Performance Tests

Voltage Sag Test

We conducted tests to examine voltage sag, a natural process where the battery voltage drops as the starter draws current.

Among our contenders, the conventional battery experienced the most sag, followed by the lithium, AGM, and gel batteries.

Cold Conditions Test

The cold weather performance varied, with AGM performing better due to its fiberglass insulation, followed by the gel battery, which experienced increased resistance due to stiffening in cold temperatures.

However, lithium batteries require careful handling in cold conditions due to the risk of forming dendrites if charged below zero degrees Celsius.

Recharge Speed Test

In a test to gauge recharge speed, the gel battery outperformed others by recharging in 112 minutes, followed by the AGM and conventional batteries.

Surprisingly, the lithium battery recharged slower due to the charger’s smart function, which modulates the charge based on the battery’s capacity.

Storage Performance Test

In a 60-day storage test, the lithium battery demonstrated superior power retention. The conventional, AGM, and gel batteries required a trickle charger over winter for optimum performance.

Capacity Test

Lastly, we conducted a test to measure the actual capacity of the batteries. Despite claiming a 9 amp hour capacity, the lithium battery showed a lower capacity due to its specific chemistry and construction.

Features and Benefits

Battery Type	Key Features	Benefits
Conventional	Lead-acid, heavy	Cheap, reliable
AGM	Fiberglass mat, sealed	Safe, durable
Gel	Silica-based, spill-proof	Heat-resistant, spill-proof
Lithium	Lithium iron phosphate, lightweight	Mountable in any direction, superior power retention

Final Thoughts

All four types of batteries demonstrate strengths in different areas:

Conventional: affordability and reliability
AGM: safety and durability
Gel: heat resistance and spill-proof construction
Lithium: flexibility of installation and power retention

Choosing the right battery for your motorcycle will ultimately depend on your specific needs and budget. It is essential to understand each battery type’s unique features and benefits and balance these factors against their cost.