There are several types of motorcycle batteries on the market, and it can be confusing trying to unravel the differences between each and if they are suitable for your bike.
Here we have gathered all the information you need about the various types of motorcycle batteries out there so you can purchase your next replacement battery with confidence.
Let’s get started.
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Wet Cell Batteries (Lead Acid)
Wet Cell batteries are also known as lead-acid or flooded cell batteries.
They are easily distinguished by a row of plastic stoppers that sit on top of the battery. There will be a row of 3 for a 6 Volt battery and a 6 for a 12 volt.
Traditionally wet cell batteries have an opaque clear casing on the bottom and have a high and low-level indicator painted on the front.
Lead Acid batteries hold the electrolytes in a liquid acid and give off Hydrogen gas when charging or discharging.
The batteries need to be topped up regularly with distilled water as the water portion of the acid mix can evaporate and get used up over time.
By checking the upper and lower level indicator marks on the battery, you will see if the battery needs topping up.
They are not a good option for motorcycles simply because they are not sealed and prone to spillage (as bikes tend to lean over in bends etc.)
- Easy to find and purchase
- The Hydrogen gas emitted is both toxic and explosive. Store and dispose of wet cell batteries safely.
- Maintenance of these batteries is essential.
- The liquid inside can move freely, and therefore wet cell batteries are very vulnerable to spillage.
Absorbed Glass Mat (AGM) Batteries
AGM batteries are a step up from conventional wet-cell batteries, although they do operate similarly.
They also use lead-acid; however, the liquid is trapped between sheets of fibre-glass. So should a battery be knocked over, there will be no spillage.
AGM batteries have a pressure-relief valve that allows some of the Hydrogen and other gasses to escape when needed.
Not as much gas is expelled as a wet-cell battery, so there is no need to top an AGM battery up with distilled water continually.
It is important never to open up an AGM battery as the outside air can poison the gas and lead-acid in the battery.
AGM batteries need to be charged low and slow. Hence, you must use an AGM battery charger that can alter the Voltage to ensure the battery is charged properly and functions at its optimum capacity.
AGM batteries are quickly replacing wet cell batteries as the most common battery on the market. This is thanks to the fact they have solved the problem of not needing to keep them topped up and lack of spillage.
AGM batteries are suitable as motorcycle batteries as they are sealed, unlike traditional wet-cell batteries.
- Affordable compared to other battery types
- Common – easy to find
- No need to keep topped up with distilled water
- No spillages of lead-acid as the unit is sealed
- Need to ensure the battery charger you use is specifically suitable for AGM batteries
- Despite emitting less gas than wet cell batteries, the gasses released are toxic, and therefore the battery should be treated with care and stored safely
Gel Cell Batteries
Gel cell batteries work differently from traditional wet cell batteries and AGM’s.
Gel battery electrolytes are stored in a silica gel; this gel state is then encased into a unit and hermetically sealed (a type of sealing that means it is air-tight).
The lead-acid used to mix with silica to make the gel is the same form used in wet cell and AGM batteries; it is just a different texture.
Gel cell batteries do not need topping up, need their levels checked or to be opened at any point.
These batteries, when being charged, create pressure which mixes the oxygen and hydrogen back into the water with the gel to form electrolytes.
As with the AGM battery, there is a pressure-relief valve.
Essentially thanks to the gel form and pressure valve, these batteries are also spill-proof.
They also serve better in hot weather as the technology keeps the battery cooler than wet cell/AGM batteries.
Gel batteries have a higher power-weight ratio which means they are more compact and have better performance.
They are suitable for newer bikes but are often not compatible with older motorcycles.
- Great for motorcycles that spend time leaning over, such as dual-sport and sportsbikes, these batteries won’t spill thanks to the gel form
- No maintenance required in the form of topping up and checking levels
- Good option for hot weather as they stay cool
- Emit less gas than wet cell batteries
- Vibration Resistant
- Can be installed in any position, which makes them a good choice for custom bikes
- Long charge cycles need to be charged low and slow and removed immediately when fully charged so as not to ruin the electrolytes by overcharging
Lithium-ion batteries are the newest addition to the market, and the technology is still relatively new compared to traditional batteries.
They are lightweight compared to traditional batteries. Any weight saving on a motorcycle is always a massive benefit.
However, if your bike is running a lot of electronics such as a USB point and a tracker from the battery, you will find the power runs out pretty quickly, and you will be out of juice more often than you would with other types of battery.
You will need a lithium battery charger to charge your battery; this is very important. You need to watch how many volts are running to the battery as overcharging or charging too quickly can lead to permanent damage.
Fortunately, most batteries on the market today come with a Battery Management System (BMS) installed, this will prevent overcharging and also stop the battery from completely discharging. A dedicated charger will communicate with the batteries on-board BMS to ensure peak performance.
Careful maintenance is essential for lithium-ion batteries.
- Plenty of cold-cranking amps
- No spillages
- Discharge a lot slower than traditional batteries
- Suitable for aggressive on and off-road riding
- Cannot be overcharged (modern batteries utilise a BMS to prevent this)
- Cannot be discharged too low as they will be permanently damaged (modern batteries utilise a BMS to prevent this)
- Technology is still very new and in motion, so won’t be suitable for many bikes
- Not great for bikes with loads of electronics to run
What is the right type of battery for a motorcycle?
To understand which battery is the best out there, we need to compare them some more; there are some significant differences.
Type of Lead Acid Combination Used
Wet cell, gel cell, AGM batteries all use the same type of lead-acid. The only difference is how it is stored within the actual battery unit itself.
Wet cell batteries are prone to spillage as the acid flows freely throughout the battery, and it is not sealed in the same way as other batteries. They also expel the most toxic gasses and require topping up, unlike the other lead-acid battery forms.
AGM batteries are sealed, and the liquid is contained within the unit, so spillages can’t happen.
Gel Mat batteries are air-tight sealed and the lead-acid is mixed into a gel state, so it is not free-roaming.
Gel Mat batteries are therefore the best option when it comes to lead-acid based batteries.
Lithium-Ion batteries do not use lead-acid and operate differently.
All motorcycle batteries carry an element of risk.
Wet cell batteries are prone to spillage and the gas emitted can happen in quite large amounts; it is toxic and explosive.
Therefore an AGM battery is a better choice for a wet cell type battery as the liquid is sealed, it cannot be spilt and emits less toxic gas.
However, overall, gel cell batteries are pretty safe; they can be fitted at various angles as they won’t spill thanks to the gel form; they emit minimal gas.
They can undertake heavy riding and vibrations, further to which they are less likely to be affected by changing temperatures.
Lithium-ion batteries are considered very safe, or they would not be in production for motorcycle use. Electric motorcycles that are coming to the surface are fitted with lithium-ion batteries.
However, they can overheat quickly if overcharged. A battery fire is not fun and very dangerous.
Wet cell batteries are the cheapest of the bunch, followed by AGM batteries. They are the most common types of battery on the market and are priced competitively.
Gel cell batteries, however, do not come cheap, thanks to the gel technology used.
Lithium-ion batteries are the most expensive option; being the newest to the market, they are also not the easiest type of battery to find for individual bikes.
Overall when compared, the best motorcycle battery type is the gel cell battery.
It is more expensive than the other lead-acid batteries; however, its advantages are worth the extra cost.
If a gel cell battery is out of your budget, it would be best to go for an AGM battery as the battery acid is sealed and therefore has an increased level of safety.
Lithium-ion batteries will likely develop and eventually infiltrate down to be more affordable and are an excellent option if available in the right size for your bike.