You probably hate those times when you want to ride your motorcycle and find that the battery is flat. There is no charge and your bike’s engine will not start. It is not wear and tear or age that are the most common causes of batteries failing. During the time that your bike is parked up and not being used, the battery slowly loses its charge and sulphation occurs . If you don’t keep your battery charged either by riding the bike, or using a battery charger, it will eventually get to a stage where the sulphation causes a short-circuit. Then you won’t be able to start your bike – or recover your battery. You can expect a motorcycle battery to last around 4 years on average before its performance tails off. This is the time when you need to consider a replacement battery.
Motorcycle parts store can supply a battery from our wide range of quality batteries from trusted manufacturers including Motobatt , Yuasa and JMT . A battery charging system is an essential piece of kit for a motorcyclist and MPS also has a wide range of battery charging systems and accessories to help you keep you battery fully charged and and maintained correctly.
How does a motorcycle battery work?
A motorcycle battery stores electrical energy by using a reversible chemical reaction between the lead and the acid in a battery. Battery Electrolyte is a mixture of sulfuric acid and distilled water and is used as a conductor to create an electrical charge and provide energy to the electrical circuits of the vehicle.
A battery’s chemical process is never-ending. It cannot be turned off. When not being used a battery sits there idling slowly and gradually losing charge. It will take many months for the battery to completely lose its charge . This is easily preventable with a smart charger like the NOCO Genius .A smart charger keeps it topped up by delivering energy to counter that slow discharge.
What does a motorcycle battery do?
On a typical motorcycle, the battery has five different roles to play.
- Starting – Supplying power to crank the engine over.
- Lighting – Delivering power to the lighting system without the engine running.
- Ignition – Supplying the ignition system with power while the engine is cranking.
- Charging – Absorbing any spikes in power and stabilising the bike’s voltage .
- Support – Supporting areas like the bike’s other electrical system like ECU,Alarm or immobiliser when the engine isn’t running.
Choosing the Best Battery for your Bike
When you come to choose a battery for your motorcycle there are a few things that you need to consider. Its also worth investing in a suitable battery charging system to maintain and preserve the effectiveness of your battery. There are several types of battery in general use on todays motorcycles, Standard lead-acid, VRLA, AGM and Lithium. They all have their plus-points and their pit-falls . Here is a brief summary description of the different types of battery.
Types of battery : Standard,Flooded,or Wet Lead Acid
Lead acid batteries hold the battery cell’s electrolytes in a liquid acid . They give off Hydrogen gas when charging or discharging (Hydrogen gas is highly explosive and toxic!). These batteries need to be periodically checked and topped up to the upper level mark with Distilled Water. The water portion of the battery acid evaporates or gets used up over time.
Lead acid batteries have been around for a couple of centuries
A normal 12V lead-acid motorcycle battery is made up of a plastic case containing six ‘cells’. Each cell is made up of a set of lead ‘plates’ – negative plates and positive plates – which are immersed in a sulphuric acid and water solution called ‘electrolyte’.
These days, VRLA (valve regulated lead–acid) batteries are the most common ones used. These are ‘sealed’ you just need to ensure it’s fully charged. The benefit of a sealed battery is the fact it is ‘maintenance free’ – the battery acid gets heated in use and any liquid that evaporates won’t escape the battery unless during extreme conditions. The downside is that if you do boil it over, you can’t add in more acid. The battery cells form a totally closed system and any gases produced by the operation of the battery are reabsorbed into the electrolyte.
VRLA batteries have a valve that will open if the pressure inside exceeds a safe level.
Absorbed Glass Matt batteries are essentially a regular battery with glassfibre between the plates which acts like a sponge. AGM batteries are a more powerful battery for a given size, compared to a standard wet cell battery.
The sulphuric acid content in the electrolyte is much higher and an AGM type of battery can generate more power than a standard wet battery, and it is filled once then permanently sealed. These batteries can be safely mounted on their side.
AGM is the best lead-acid starter battery for motorcycles
GEL batteries like AGM batteries are sealed VRLA batteries where the electrolyte is a thick gel substance that will not easily leak out. The advantages of this are that the battery resists vibration damage and also can be positioned at an angle. Gel batteries are also less prone to sulphation, meaning if you’re the sort of person who forgets to charge your battery, gel is a good option.
Lithium-ion batteries are fitted to many new bikes, and they offer more performance whilst being lighter and smaller than the lead acid/sealed AGM type, but they do have different requirements when it comes to charging or maintenance.
A lithium battery is significantly lighter than a lead-acid battery. A typical lead-acid motorcycle battery for a litre-superbike weighs around 4kg, a lithium equivalent weighs around 750g. Lithium batteries have a better cranking power and a longer life than a lead-acid battery. Lithium-Ion batteries pack a powerful punch, so you can start an engine with a battery that’s much smaller – and lighter – than traditional lead-acid.
Lithium batteries generally offer plenty of cold cranking amps and are light-weight.They are ideal for more aggressive riding on and off road and where a minimum of electrical devices need power when the bike’s not running. However, if your bike runs lots of high-tech electronics or a tracker, the battery will run out of power pretty quickly. For long distance touring and if weight and space aren’t critically important, you might as well stick with a good quality AGM lead-acid battery.
There are some other downsides to Lithium batteries. Lithium motorcycle batteries are safe if they’re treated properly, but if you overcharge a lithium battery it can catch fire. So if you’re thinking of changing from lead-acid it’s essential to check that your bike’s charging system is suitable. The safe upper limit for a lithium motorcycle battery is 14.6V. The worst thing for a lithium battery is being overcharged and you really don’t want to do that.
A lithium battery has a much slower self-discharge rate than a lead-acid battery, but most modern bikes draw some power even when parked up (and especially if they have an alarm or tracker). Lithium cells must not be discharged too far or they’ll be permanently damaged, so you’ll also need to buy a charger that’s designed for lithium packs.
We hope that this article helps you to understand the different types of battery and how to choose a battery for your motorcycle. You might want to take a look at these other articles we have about battery related issues. If you are looking to purchase a replacement battery for your bike then you can be sure that MPS can supply you with one from their range of quality batteries at a competetive price.
Read our article about battery chargers available from MPS or browse the full range of battery chargers