Take care of your batteries during the offseason. That may mean removing them from your boat and keeping them in a climate-controlled building. Check them occasionally and top off the charge as necessary.
May 22, 2025
By Thomas Allen
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For many of us, there is no offseason. And that’s a good way to live. However, if you call the Ice Belt home, boat winterization is a real thing, and a sad thing at that. Fortunately, we have a season full of deer-hunting and ice-fishing memories in the works. Keep your chins up.
As the countdown to spring fishing begins, the last thing you want when you pull your rig out of moth balls is for nothing to work—or worse yet, ruined batteries, missing gear, and mice. Nobody has time for that.
The steps you take now to store and maintain your boat, graphs, and batteries assure a smooth relaunch next spring. For the sake of our discussion here, the following process applies to any type of battery—lead acid, AGM, and lithium —and any brand of electronics. Each item is on a list that represents an investment; you owe it to yourself to get the most out of everything—that means maintenance.
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The Boat, Briefly Your boat requires a few preventative maintenance tasks to be fully winterized, especially if the rig is to be stored outside or in a non-temperature-controlled facility. To start, add some fuel stabilizer to the gas tank(s). Star Brite Star Tron is our treatment of choice at In-Fisherman . Also, run some antifreeze through your livewell and bilge lines, which helps keep any remaining water from freezing that could crack the lines.
Fog the cylinders in your outboard—simply pull the plugs, give each port a couple squirts of Star Brite’s Fogging Oil , and you’re set. Remember, installing new plugs next spring is always a good call. Changing your engine’s lower unit lube also is important before storage, to prevent freezing in case any water has found its way inside. It also helps to prevent rusting and corrosion inside the gear box over winter.
If this process isn’t in your wheelhouse, taking it to a dealer to have it professionally winterized is a good idea.
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Oh, and I’d place at least half a dozen mouse traps throughout, just in case. Can’t be too careful when it comes to unwanted rodents. I’ve learned this lesson the hard way.
Batteries Modern batteries, especially lithiums, are expensive and require a certain level of maintenance and oversight during the offseason. Just keep them warm, dry, and charged to be ready to roll when spring arrives. First, let’s debunk a myth: You can indeed leave modern lead-acid and AGM batteries on the concrete floor without risk of the battery getting ruined. I was brought up to believe that you needed to store them on a piece of wood, as the concrete would allegedly draw out moisture, rendering it useless. While that was the case 30-plus years ago, you don’t have to worry about it. Most batteries are double insulated, and the hard plastic shell adds an additional layer of protection. Lithium batteries are not affected by sitting idle on concrete, either. So, if there is a convenient place on your shop or basement concrete floor, stage them where it makes sense during the offseason.
Extended periods of storage with persistent cold temperatures wreck a battery faster than anything. For that reason alone, I highly recommend pulling every battery from your boat and storing them inside. It’s just a good idea for the sake of maintaining and monitoring their condition. Plus, it’s a cheap insurance policy to get you on the water right away next spring.
At In-Fisherman HQ, we pull all the batteries from our fleet of boats and store them on a cart that holds up to 24 batteries with two on-board-type Minn Kota chargers attached to the side for occasional charging and maintenance.
If you keep them in a convenient location, you’re far more likely to take note on each battery’s current power state. Hook them up to a charger once or twice while in storage. Most of today’s lithiums come standard with a BMS (battery management system) that connects to an app on your smartphone for fast and easy monitoring. Charge as necessary.
Battery Chargers An on-board charger like Minn Kota’s Precision chargers allows for constant connection to maintain the charge without having to disconnect when fully charged. This is an ideal method if your boat is stored inside a temperature-controlled facility during the offseason. Speaking of chargers, there are a couple variations and applications to keep in mind. When storing your rig in a temperature-controlled building, keep the batteries installed and the on-board charger plugged in. Minn Kota Precision chargers maintain batteries without any babysitting required. In fact, with regard to my personal boat, I generally leave it plugged in all winter in my climate-controlled shop and have never had an issue.
Trickle chargers are easy and effective but need to be monitored. If you plan to charge individual batteries once or twice during the offseason, this is a good option. But don’t forget about them. You can ruin a battery by leaving it connected to a charger that is not a maintainer. Most lithium batteries come with unique chargers that are not maintainers. In each case, keep an eye on them and disconnect after the charging cycle is completed.
Graphs and Updates Take advantage of the winter months by making sure your graphs carry the most recent software versions. Also, if you have a collection of Lakemaster map cards, organize them so you know where each is located when the ice melts. Organization and regular maintenance are critical to a headache-free first trip once the offseason closes. Before you park the boat or get it shrink-wrapped for the winter, remove all your graphs for cleaning and updating. While built to withstand brutal elements, storing graphs in the bitter cold is not good for them. There’s no better time to make sure the power, GPS, and sonar ports are free of debris, and the screens are without smudges or fingerprints.
Warm, soapy water is quite effective when dealing with stubborn water spots. Otherwise, when cleaning touchscreen graphs, avoid ammonia- and alcohol-based cleaners as they have been proven to damage touchscreens. Sparkle Glass Cleaner , available at Menards or Amazon, works very well and meets all the necessary criteria to safely clean your graph screens—wipe it off with clean microfiber towel. It’s also worth noting that it doesn’t take much to soil a microfiber towel; if it’s smearing more than it’s helping, get a new one.
Regardless of brand, all electronics companies generally put out a couple of software updates per year and overall performance depends on the user regularly installing these updates. If an update or two has been missed, you might need to go back and install them in chronological order for the most current software to function. This process takes commitment from the beginning, but falling behind eventually affects on-the-water performance.
This is another good reason to keep a battery handy. In fact, right next to a lithium battery and charger, I have a Ram Mount on my workbench to accommodate all the units we run on our boats, which allows for convenient updating and cleaning. I can sneak down into my basement, toddy in hand, and work through my winter maintenance checklist as time allows.
To manage our boats, we pull each battery and store them inside In-Fisherman HQ during the winter. This custom-built cart makes it easy to move them around and keep them topped off. Even when the boat is parked for a few months, don’t neglect a few simple chores that ensure a quick re-rig and launch when spring returns. Take advantage of the downtime now to update and maintain your equipment so it continues to work for you without issue.
