Seasonal Vehicle Battery Maintenance: Why and How

An average car battery lasts 4 to 5 years, maybe even up to 7. But where and how you drive, and what the weather is like in your area, affects its lifespan. Lots of short trips are harder on your battery than long trips. 

As long as you’re not having an obvious problem, you can ignore it. But it’s a good idea to have your car battery checked every fall. Because summer heat may have caused invisible damage, and you’ll likely see its effects in winter.

Why Does Corrosion Occur on Battery Terminals?

Hot weather is the toughest environment for car batteries. When it’s 30 or 35 degrees outside, it’s 60 to 65 degrees under your hood. These high temperatures can cause the water in your vehicle’s battery to evaporate. High heat can also force some of the fluid out through the battery’s vent holes as gas. This causes a chemical reaction with the lead and other metals in the battery connector. If you’re seeing white or blue crystals, or salt-like corrosion, on the + and – terminals, this is the reason.

A battery that’s overcharged is more prone to corrosion, and it’s usually more pronounced at the positive terminal.

About half of early battery failures are caused by fluid loss in the battery. You may not see this damage, but it reduces your battery’s efficiency.

How Can You Perform Battery Maintenance in Summer?

Avoid deep discharges. Parking by the lake and listening to music from your car’s stereo is fun, and charging your phone from the 12V outlet while camping is convenient, but significantly draining the battery can damage its internal components.

Park the car in the shade whenever possible. Keeping the temperature under the hood a bit lower than it would otherwise be will slow down fluid evaporation.

Speaking of battery fluid, faster evaporation in hot months will increase corrosion. Clean the corrosion on top of your battery once a year and make sure the cables are securely connected. 

Cleaning Corrosion on Battery Terminals

The best and easiest way to clean corrosion is using baking soda and hot water. Apply a bit of water and baking soda (or dissolve some baking soda in a little water) and clean the corrosion using an old toothbrush or similar tool. Rinse thoroughly with hot water.

Make sure to wear protective glasses and gloves — if battery acid/corrosion gets on your clothes, it will eat holes in them. It can also damage your vehicle’s paint.

Why Won’t the Car Start When It’s Cold Out?

If you drove a lot over the summer, or if it’s been very hot, your vehicle’s battery may not be as efficient come fall, for the reasons above. If it’s not working properly, it will have trouble holding a charge and delivering starting power to the engine.

Noticing that your vehicle starts slowly on cold mornings but more easily in the afternoon is a sign your battery needs maintenance. This is because all the fluids in your vehicle become thicker when temperatures drop, like syrup straight from the fridge instead of at room temperature. Because of this, moving the engine oil needed to start the engine requires more power. Also, the chemical reactions taking place in the battery are slower in the cold.

Simply put, your vehicle’s systems need extra output from the battery to run in colder conditions. If your battery is old, needs recharging, or can’t hold a charge, it will struggle to perform in cold weather.

How Is Battery Maintenance Done in Winter?

First, get your battery tested in fall, between the summer heat and winter cold. A test will tell you whether the battery is fully charged, how many cold-cranking amps it can deliver, and how healthy it is overall.

If you drive your vehicle less often in colder months, frequently take very short trips, or have trouble starting it in the mornings, keep a charger on hand and use it. If you live in a very cold climate where temperatures can drop to -15°C, consider using a block heater or a battery blanket.

A block heater will warm your engine, making it easier to start the car. A battery blanket, as the name suggests, keeps your battery warmer so the fluid keeps moving, making it easier for the battery to deliver the necessary amperage when it’s cold outside. Depending on where you live, you may want to use both of these items — talk to a mechanic to find out what you need.

Keep jumper cables in your car, since you’ll need them more often in winter months.

As you head into the colder months, take a few minutes to clean the corrosion on top of your battery and make sure the cables are securely connected.

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