How Do I Keep My Car's Battery Healthy While in Storage?

If you’re here, you’re probably part of one of two camps: Either (A), you need to store your car over the winter without the battery going flat, or (B), you need to store your car for even longer than that without the battery going flat. Regardless of which boat (or rather, garage) you find yourself in, keeping a battery healthy over long periods of disuse can be a little tricky.

Let’s get the first and most obvious solutions out of the way first. If you’re looking to store a car over winter, for example, you’ll want a charger. Generally speaking, there are three main types of battery chargers that can be used to keep your battery topped up when your car isn’t doing it for you. Most cars will, but once they stop being driven, that battery begins to lose its charge.

The first solution is a run-of-the-mill regular ol’ car battery charger. Generally, these will be used to quickly charge a battery that’s already gone flat. This is your solution if you’re now reading this from your garage next to a car that could’ve maybe been stored better over winter. Be warned, even regular chargers will take a good while to get a flat battery up to a usable charge again. Really, this isn’t the best solution if you’re looking to keep a battery healthy in storage.

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By far the most popular solution is a trickle charger. Unlike a standard charger, which constantly puts out its maximum voltage until the battery is fully charged, trickle chargers gradually add charge over time, which is much better for a battery that’s already holding a charge. For that reason, it seems like a perfect solution, but there’s something to be mindful of: neither the traditional charger above nor the trickle charger, typically features a cutoff. Without that cutoff, both will run for as long as they are plugged in, eventually damaging your battery.

However, some trickle chargers feature a “float” mode, like the one made by Battery Tender. The brand’s float mode does what it sounds like- once a battery is full, the charger will automatically switch to maintaining this charge, rather than slowly adding to it. As a result, you don’t have to worry about overcharging your battery while using this. Plus, the brand’s 4A Car Battery Charger is switchable, allowing you to move between 6v and 12v outputs as needed.

There’s a final category as well: maintenance chargers. These will also solve the problem of overcharging. They’re basically a smarter trickle charger that reads a battery’s voltage. Once the charger’s little brain reads that the battery is full up, it’ll taper off and eventually stop the flow of electricity. Then, once the battery charge begins to dwindle again, it’ll pick the charging back up.

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Battery Tender makes maintenance chargers too, but we’re also fans of the NOCO Genius10. Like the above Battery Tender item, this maintenance charger is switchable between 6v and 12v outputs, which means it’ll fit a range of batteries. It’s also compact, at less than 5 inches long, and features a handy readout to tell you which of the tender’s various modes you’re in, as well as your battery’s current state of charge. As an added bonus, the Genius10 will also work with a number of other battery types for different vehicles.

Really, a maintenance battery charger is the best way to keep the battery alive in a car that isn’t being regularly driven. You don’t need to remove the battery from the car, and as long as you’ve got access to a standard 12-volt outlet, you’re able to keep the battery going for a long while.

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Chase Bierenkoven
Chase Bierenkoven

Chase is an automotive journalist with years of experience in the industry. He writes for outlets like Edmunds and AutoGuide, among many others. When not writing, Chase is in front of the camera over at The Overrun, his YouTube channel run alongside his friend and co-host Jobe Teehan. If he's not writing reviews of the latest in cars or producing industry coverage, Chase is at home in the driver's seat of his own (usually German) sports cars.

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