If you take a road trip on your motorcycle and find yourself stuck in a small town in the middle of nowhere with a flat battery and are wondering whether the spare 12V battery Farmer Brown has in his workshop will work in your motorcycle, think again.
You cannot use any 12V battery in a motorcycle because each battery is a different size and has a different cold ranking amp. You should only use the 12V battery specified by the motorcycle manufacturer.
The primary function of a motorcycle battery is to provide power to the starter in order for it to crank the engine. It also provides the voltage needed for the electrical components, like lights and gauges to function properly. Although all motorcycle batteries are all 12V (except for vintage motorcycles) not all 12V batteries are the same.
12-volt Motorcycle Batteries Are Not Universal
There are 3 or 4 main groups of 12V batteries used for motorcycles. Within these groups, each battery has a different size and a different cold cranking amp rating. So, 12-volt batteries are the same, but different and it is essential that you use the right one for your particular motorcycle.
If, for example, you tried to start a 1000 cc motorcycle with a battery from a 125cc motorcycle it would sound as if the battery is dead because it only has 50 cold-cranking amps (CCA). The CCA rating indicates how many amps can flow through the battery at 0 degrees for 30 seconds without dropping below around 7.5 volts.
A battery from a 125cc motorcycle is not going to have enough power to crank an engine with a higher compression ratio. You will need to know the CCA of the 12v battery you want to use in your motorcycle to make sure it is the same as the CCA specified by the motorcycle manufacturer.
12-volt batteries also have varying Amp Hours (Ah). This indicates how long a consistent voltage can be supplied to the engine before the battery drains completely. The Ah required by your motorcycle will depend on the number of electronics installed.
Then there is the size of the battery which is the differential that is the main reason 12V batteries aren’t universal. A motorcycle with a bigger frame will be designed to use a battery that has larger dimensions than a motorcycle with a smaller frame so, even if the CCA and the Ah match, the battery may simply just not fit. Likewise, a battery that is the right dimensions may not have the correct CCA or Ah for your engine.
Types Of Motorcycle Batteries
- Lead-acid Battery: This is the most basic battery where battery acid floods lead plates causing an electrochemical reaction that generates the power needed. These are usually the most inexpensive batteries but aren’t that durable, especially in off-road bikes. They also don’t like cold weather!
- Absorbed Glass Mat or AGM batteries: These batteries have fiberglass mats between the lead plates which absorb the acid. They cushion the plate and act as a sponge keeping the battery acid against the plates. They are pricier than regular batteries and do not like being overcharged but are extremely durable.
- Gel batteries: These are batteries where the acid is suspended in a gel substance. They are not good for starting powerful engines as the amperage is too low. One advantage is that they don’t have to be upright when in use.
- Lithium-ion batteries: These batteries have lithium and graphite coated in an ethylene electrolyte that causes the electrochemical reaction needed. They are smaller and lighter in weight than other batteries so are ideal for racing motorcycles. They are protected from overcharging and charge quickly which adds to their suitability for racing.
Of these batteries, the most commonly used are the Lead-acid and the AGM. The Li-Ion is becoming increasingly popular due to its performance and longevity.
In order to keep your motorcycle running as it should, it is best to use a battery that matches the specs of the original battery. If you don’t have a manual or the original battery you should be able to find out from one of the many online databases or ask at your local motorcycle shop. As long as the CCAs, the Ah’s, and the dimensions match, you’re good to go.