Battery Selection, Activation & Charging

Battery Selection, Activation & Charging for motorcycle and powersport batteries

Selecting a Battery

Selecting the right battery is an important decision as it will ultimately affect customer satisfaction. Battery problems are often caused by the selection of the wrong battery for a specific application. There are two sources for identifying the right battery for an application.

Find the right battery for your motorcycle here

View our motorcycle application guide

Yuasa may list more than on battery for a specific vehicle. Be careful when matching a new battery with what’s installed in the vehicle—make sure that it is the correct battery or the same “problem” may be repeated causing the battery to be replaced again. If the engine has been modified and has higher compression or larger displacement, a battery with more starting capacity like the High Performance AGM types would work well. If the bike will not be operated for long periods of time the AGM or YuMicron batteries are a good choice.

About Sensors

Many powersports vehicles that use Conventional batteries come equipped from the factory with battery sensors. The sensor indicates battery electrolyte level by flashing a warning light on the vehicle’s instruments panel. This indicates that it’s time to add water to the battery.

Battery sensors are matched to each battery and are not interchangeable. Even if the battery sensor is original equipment (OE) it must be changed when replacing the battery because it may not match the new battery.

Activating a Battery

Yuasa batteries come from the factory in one of two ways: Factory Activated (FA) where the battery is filled with electrolyte, sealed and charged at the factory. These batteries must be used within a period of time and cannot be stored indefinitely. The other type of battery is shipped dry and can be either a Conventional or AGM type of battery. These batteries are sometimes referred to as Bottle Supplied (BS) because they are shipped with the electrolyte stored in a plastic container. The battery is filled with electrolyte from the container when it’s ready to be activated. Once it’s unsealed, a battery should be activated, charged and installed. The plates of an unsealed battery will begin to oxidize making it more difficult to charge later.

Smart Chargers

A battery charger brings a new battery, or a battery that has been discharged, to full capacity. Battery chargers send direct current (DC) into the battery flowing in the opposite direction of current when the battery discharges. In addition, charging a battery reverses the destructive chemical process (sulphation) that takes place as the battery is discharged. The lead plates and electrolyte, which transform into lead sulphate and water during discharge are changed back to lead antimony (Conventional battery), or lead calcium (AGM battery). The charging process returns the lead sulphate and water to their original states.

Smart Battery Chargers are the best types of chargers in that they combine both constant current and constant voltage technology. The strong charging characteristics of a constant current charger are used to initially charge the battery; then the charger automatically switches to a constant voltage mode to float-charge or maintain the battery. Smart chargers monitor the battery’s state-of-charge and will automatically start charging when the battery falls below a specific voltage. This smart technology is also used to keep batteries from being over-charged, thereby reducing water loss in Conventional batteries.

Points to Note

  • Automotive or high-rate types of battery chargers should not be used as they can overcharge and damage small batteries
  • Always match Conventional or AGM batteries to the correct battery charger. The wrong type of charger, or a charger that outputs too much amperage can cause poor performance or even permanent damage
  • Do not use a high-amperage charger to reduce charging time as it will void the battery warranty

To find the recommended charger current output in amps for a specific battery, divide the battery amp hour rating by 10. For example a 14AH battery should be charged at 1.4 amps (14AH ÷ 10 = 1.4 amp current). Select a battery charger that comes closest to the value of that figure. All Yuasa powersport batteries have the amp hours printed on the front or top of the battery case.