Battery Tenders and Winterizing a Motorcycle Battery
Reviewed by CrankDex editorial
A motorcycle battery that sits unused all winter is one of the most common ways riders end up buying a new one every spring. A smart maintainer, used correctly, mostly solves that.
Winter storage is where a lot of otherwise healthy motorcycle batteries quietly die. Left alone for months, a battery slowly self-discharges, and a lead-acid battery sitting too long at a low state of charge can develop sulfation that eats into its capacity. The fix is simple in concept: keep the battery charged the whole time it sits. The details of how you do that matter more than people expect.
Smart maintainer, not a dumb charger
A smart maintainer (often called a battery tender) charges the battery and then switches to a low float mode that keeps it topped up without overcharging it, and it can safely stay connected for weeks or months. A basic, "dumb" high-amp charger, the kind meant to quickly charge a large car battery, isn't designed to be left connected indefinitely and can push too much current into a small powersports battery, overheating or damaging it. If a charger doesn't mention a float or maintenance mode, it's not the right tool for long-term storage.
The lithium caveat
This is the one detail that trips people up when they upgrade to a lithium (LiFePO4) battery: an old lead-acid trickle or desulfating charger is not automatically safe for lithium. Lead-acid chargers sometimes use desulfation pulses or a float voltage tuned for lead-acid chemistry, and pushing that into a lithium pack can damage it over time. Use a charger with a dedicated lithium / LiFePO4 mode, or a modern smart charger built to detect and handle both chemistries correctly.
Leave it in the bike, or take it out?
Both approaches work. Leaving the battery in the bike and running a maintainer lead out to it is the simplest option and avoids any risk of forgetting to reconnect cables correctly later. Removing the battery and storing it indoors, somewhere cool and dry, on a maintainer is a good option if the bike is stored somewhere very cold, damp, or hard to get to, or if it's just easier to keep an eye on the battery where you can see it. Whichever you choose, the maintainer is what actually protects the battery, not the location by itself.
Before you put it away
A quick check before winter storage pays off. Clean the terminals of any corrosion so the maintainer has a good connection, and give the battery a full charge before connecting the maintainer rather than assuming it's already topped up. If the battery is already a few years old and has been showing any signs of weakness, going into winter is a good time to consider replacing it rather than finding out it failed in spring.
Checking on it during storage
A maintainer mostly runs on its own, but it's still worth a periodic glance, especially early in the season, to confirm it's actually connected, powered, and showing a normal charge or maintenance indicator. A maintainer that's unplugged, or plugged into a dead outlet, isn't doing anything.
Browse smart battery maintainers on Amazon (we may earn a commission, at no extra cost to you). If you're storing a lithium battery, double-check the charger lists a lithium or LiFePO4 mode before buying.
Frequently asked
Do I need a battery tender for my motorcycle over winter?
If the bike is going to sit for more than a couple of weeks, yes, a smart maintainer is the easiest way to prevent the battery from self-discharging, sulfating, or freezing in extreme cold. It's inexpensive insurance against needing a new battery in spring.
Can I use a car battery charger on a motorcycle battery?
It depends on the charger. A basic high-amp charger meant for large car batteries can push too much current into a small motorcycle battery and overheat or damage it. A smart maintainer designed for powersports batteries, or one with a low-amp motorcycle setting, is the safer choice.
Can I use a regular charger on a lithium motorcycle battery?
Not safely. An older lead-acid charger, especially one with a desulfation or equalization mode, can push voltages or pulses into a lithium (LiFePO4) pack that it isn't designed to handle. Use a charger with a dedicated lithium mode, or a modern smart charger that detects the battery chemistry.
Should I remove the battery from the bike for winter storage?
Either leaving it in the bike on a maintainer, or removing it and storing it somewhere cool and dry on a maintainer, works well. Removing it is mainly useful if the bike sits somewhere very cold or damp, or if it's simply easier to keep an eye on the battery indoors.
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