Lithium Motorcycle Battery vs. Lead Acid Battery Comparison

Should you replace a lead-acid motorcycle battery with a lithium cell?

Without a motorcycle battery, you'd have a tough time getting the bike's engine fired. And when it's time to replace the battery, is it worth the extra cash to install a lithium-type battery instead of the tried-and-true lead-acid battery? Today on MC Garage we take a look at lithium-based batteries.

We've covered the subject of batteries more than a couple of times here on MC Garage, but as an integral part of your motorcycle's electrical system, there is always plenty to talk about. We've covered the different types of batteries, how to replace them, and how to take care of them when you're not riding. But often I get the question, are lithium-based batteries worth their higher cost?

The short answer is yes. They are lighter, have a slower discharge rate, and perform better in cold temperatures. But they are more expensive and could require special chargers depending on the type. So let’s weigh the pluses and minuses.

First the minuses. Cost is always a consideration for when buying parts for your bike, and the difference between a lithium-based battery and your typical sealed lead-acid battery could be significant. Typically a lithium-ion battery could be anywhere from 50 to 200 percent more expensive than it's lead-acid counterpart. But lithium iron phosphate batteries like this Shorai are nearly the same cost. Do factor in that you will need a special charger, but any charger that does lithium will also do lead-acid. So maybe it was time for a new charger as well?

The only other downside is if you let the voltage drop below a certain threshold (which varies depending on the construction and brand), the battery could be toast. Lead-acid batteries recover from deep discharging better and more often than lithium batteries. Those are really the only two minuses, and there are plenty of upsides.

Next the pluses. Weight is always touted as the big reason to switch, and there is no denying that a lighter motorcycle is better-handling motorcycle. This Shorai is a third of the weight of the stock unit in this KTM 790 Adventure. "So what?" you say, "what's five pounds?" Well, the higher that weight is carried on the bike, the more you will feel it, especially when changing direction.

And on this KTM that battery is above the seat, that’s higher than your waist when sitting. With all of the work KTM’s engineers did to lower the CG on the 790 Adventure with a low-slung fuel tank and compact engine, it’s a shame to see an extra 5 pounds sat up so high on the bike. Cutting just a few pounds will make a difference.

Then there is the low self-discharge properties of lithium-based batteries. When sitting static batteries lose some of their charge, and as more time goes by, the higher loss from a lead-acid can be significant. If you haven’t ridden your bike in four months, a lead-acid could have lost up to 15 percent of its total charge—that’s if there is no draw on the battery. The Shorai on the other hand loses about 1 percent per month, without any draw, so storage life is much better. If you are storing your bike over the winder, just disconnect the negative terminal and you should be good to go in the spring.

Finally, cold-weather performance is superior. That might not be a huge concern for someone with a sportbike or naked, but adventure bikes can see freezing temps when traveling the planet. At freezing, 32 degrees Fahrenheit and 0 degrees Celsius, a lead-acid will lose 50 percent of its capacity while a lithium iron only loses 10 percent. Just a quick note, lithium-ion batteries need to be woken up and when it’s cold. Just press the starter, let the battery sit for 30 seconds and you should have all the cranking power you need.

So there it is, with lighter weight, lower self-discharge, and better cold-weather performance, all at a similar price (changer not included), a lithium-based battery’s pluses far outpace the potential downsides.