These days, there are so many options for so many battery products, it can be hard to make an informed decision. This rings true when it comes time to purchase motorcycle batteries. Not long ago you had a choice just between a flooded battery or a sealed lead acid battery (AGM). Depending on the motorcycle, ATV, or powersport vehicle it could have come with one or the other. While most of today’s cars and trucks come with a flooded battery, many powersport vehicles have transitioned to sealed lead acid batteries, and even a few are now manufactured with a lithium battery. So, which one should you purchase? We have created a guide that helps sort through the options and what might be best for your personal use.
Flooded batteries have been around in one form or another for well over 100 years. They came standard in most motorcycle and ATV applications up to the late 1980s, when AGM’s started to become more popular and affordable in the 1990s. Flooded batteries are filled with a liquid electrolyte and typically have an overflow vent. That overflow vent is connected to a rubber tube that exhaust gas and overfilled electrolyte can exit outside of the motorcycle or ATV. This type of battery requires that you check the electrolyte level from time to time. If neglected, a battery electrolyte level can drop enough to expose the lead plates causing the battery to fail. Flooded batteries are typically less expensive than their sealed AGM equivalents, so if you don’t mind the required maintenance then they can offer you a savings. While most manufacturers have phased out this type of battery, we do see them still in a few motorcycles, ATV’s, and more commonly in watersport applications such as wave runners (Jet Skis).
In the early 1980s AGM batteries started to become available, but motorcycle and ATV’s didn’t see a large move to them until the 1990s. AGM batteries like their flooded predecessors use a liquid electrolyte, but with AGM’s the electrolyte is absorbed into a fiberglass matting within a sealed case. Once the AGM’s electrolyte has been fully absorbed it is considered non-spillable and can be installed standing up or laying on its side. This meant no more acid leaking onto your motorcycle or ATV’s frame! Another major benefit was the increase in cranking power! With the electrolyte being suspended in the fiberglass matting it offered an improved reaction between the acid and lead, which resulted in a higher cranking performance than its flooded counterpart. Today a majority of motorcycle and ATV manufactures use AGM batteries as their OEM equipment.
Around 2009 lithium batteries started to come onto the market for motorcycle and ATV applications. The LifePO4 Lithium battery offers a higher cranking performance in a much smaller form factor and is lightweight. Both benefits were huge factors for the motocross and racing community. Today these lithium batteries can be charged off the existing charging systems in newer bikes post 1990 without any adaptions. Pre 1990 applications typically didn’t charge into the 14-volt range, so updating the stator is recommended. While these batteries do offer higher cranking and are lighter weight in design, they do come with some drawbacks that shouldn’t be ignored.
Lithium powersport batteries are a moderate climate battery. In cooler weather, the lithium resistance is greater, so they may need to be warmed by turning on the electronics for a minute or two before starting the application. The energy being drawn from the battery will warm the battery cells thus lowering the lithium resistance. This allows it to turn the starter better. Due to their cold-weather limitations, they should not be used in applications that are primarily in freezing weather such as snowmobiles as most only have an operating temperature down to about 0°F.
While lithium batteries can perform in warmer climate, we do not recommend them in extended high heat scenarios. Prolong exposure to high heat situations can reduce battery longevity, so we typically won’t recommend them to customer that are constantly riding in temperatures above 100°F. We also don’t recommend them being installed in applications where the battery is installed directly on the engine or has an oil pan surrounding the battery as do some Harley Davidson models.
Lastly, Lithium batteries are only 1/3 the actual capacity of the battery they will typically replace, even though they perform much better. Essentially, they act a bit more like a capacitor than a typical lead battery, meaning lots of power upfront, but not a lot of power depth available. We always recommend you purchase a lithium specific maintainer to keep them fully topped off and charged. Lithium chargers float charge a lithium battery at a higher voltage than lead acid battery chargers but also do not stay in a constant current mode. Good Lithium battery chargers also come with recovery modes should you forget to maintain the battery.
While Lithium Batteries do have their caveats, they do offer high power and solutions for custom applications. Those looking for a higher cranking battery in a smaller form factor should give these some serious consideration. Their increase of popularity has led manufacturers like KTM and Yamaha to offer a lithium battery OEM in certain applications.
As you can see, there are several options for you to sort through, and while none may be wrong, some will be more correct than others depending on your exact needs.