Battery Maintenance Tips for Reviving Stored Project Cars

Everyone knows that a crucial part of rolling that prized ride into storage is putting a trickle charger on the battery to keep it topped off. But… what if you forgot or didn’t know this was best practice? What if that car’s been in storage for more than a single season? And, what if, when you roll it out this spring, it looks like you pulled the battery from the bottom of the ocean? Should you panic and pull together $200 for a new one? Not necessarily.

Car batteries do go bad, but being crusty and unable to turn an engine over isn’t exactly indicative of failure. In fact, a lot of batteries can be cleaned up and returned to service with just a few basic tools. We’ll talk you through the process of breathing new life into a neglected battery.

Heads Up!

Batteries have acids within them that can be very harmful. Throughout the entirety of this process, you need to be wearing safety glasses and gloves to adequately protect yourself. Additionally, if you notice visible signs of damage (like a cracked or swollen housing), then replacement is your only option. Proceeding with attempting to charge it will be a moot effort at best and dangerous at worst.

As for tools, you’ll need: distilled water, a multimeter, a flat-blade screwdriver, and means of charging or jumping a car battery.

Clean the Battery

Clean terminals are critical to battery functions and maintenance. Corrosion – which usually looks like a green, blue, or white crusty substance – is a natural byproduct of battery chemical reactions. When left to its own devices, it can build up and start impeding the flow of electrical currents.

Thankfully, cleaning off corrosion is easier than you might think. In fact, a mixture of baking soda and warm water is all you need. This solution will neutralize the acid and wash away the corrosion.

Sometimes, simply pouring the water on is enough, but you can use an old toothbrush to work through any stubborn deposits. Just remember to carefully remove the terminal connections before cleaning.

Once you’re done cleaning the connections, clean off the rest of the battery with some water, a rag, and compressed air if it’s available to you.

While you’re cleaning, you also want to keep an eye out for the battery build date. It’ll generally be on a sticker on top, declaring the month and year that the battery was made. Most batteries have a service life of three to five years. If you’re past that mark, you’ll likely be better off replacing the battery than trying to revive it.

If you’d like to be thorough, remove the battery from the car. This will allow you to clean out the battery tray and remove any corrosion or residue inside it.

Check Your Electrolyte

If you’re working with a serviceable lead acid battery, you can take the additional step of checking the battery’s water levels. These batteries use a water-based electrolyte solution that will deplete with time. As it does, battery performance will drop. Luckily, you can prolong service life by simply topping off the solution with distilled water periodically.

Inspecting and topping off electrolyte levels is done by popping open the inspection cover on the top of the battery with a flat-blade screwdriver. Simply look down into the opening to see where the water level sits. You want it just below the surface of the battery; if it’s lower than that, bring the level up by adding your distilled water.

Additionally, a battery hydrometer can be used to test the state of each cell. Doing so will tell you if the battery is in good condition and can save you from wasted efforts, but isn’t entirely necessary. You can also take a battery to an auto parts store where an employee will usually conduct the same test for free.

It’s really important to wear protective gear and work carefully with this step because the solution within the battery is corrosive. You’ll want to keep a mix of baking soda and water nearby to neutralize that solution in case of accidents or for cleanup.

Trickle Charge Or Jump

With a clean battery and proper electrolyte levels, we can finally move to checking the battery’s charge. All we want to know right now is how we can move forward with charging. In any case, it’s a good idea to put the battery on a trickle charger that will bring the charge up overnight. However, cranking the engine over for other necessary spring maintenance steps might be within grasp. Using a multimeter is how we find out for sure.

Start by setting the multimeter to DC volts and connecting the negative and positive leads to the respective terminals. A good reading is in the range of 12.6-13.5 volts. Because the battery in question has been sitting without charge, it’s not likely anywhere near that. However, if it is around 11.5-12 volts, you’ll likely be able to hook a jump starter up to it and crank the car to life. Anywhere south of that, and you’re better off letting a trickle charger do the job.

The nice thing about most trickle chargers is that they will bring the battery up to a proper charge level as well as tell you if there are any issues with the battery. Some even pinpoint what the problem is. However, the charger telling you there’s a problem with the battery in any case is a good sign it’s time for a replacement.

Inspect Your Cables

Before returning the battery to service, you want to take the time to inspect the battery cables. Over time, they will corrode and break down. As they do, they’ll fail to function properly and work against the battery.

All that work we’ve done will be worth nothing without the proper connections. So, take a look at the cables and connections. Anything that’s showing signs of age or damage should be replaced now.

Better Practices Moving Forward

With a refreshed battery and clean cables, you’re ready to put everything back together and move on with your life. So long as the battery is able to reach and hold an adequate charge, you can move on to the other steps of returning a vehicle to the road this spring. That said, you’ll want to be proactive if you hope to get the most out of your battery moving forward.

Anytime a vehicle is in storage for prolonged periods, you should hook the battery up to a trickle charger. Keeping the battery charged up slows down corrosion, helping it to lead a long service life. Of course, keeping an eye on electrolyte levels in serviceable batteries is a must, too.

Since we’re talking about maintaining batteries that are up there in age, it’s also a good idea to keep a portable jump pack in your car. That way, if an issue has slipped under the radar or the battery does start to fail on account of natural causes, you have the means to get yourself to a parts store or service station to replace the battery rather than being stranded.