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How to maintain a truck battery

A well-maintained truck battery is a safety essential. You don’t want drivers worrying about flickering cabin lights, or worse, a vehicle that won’t start. A well-functioning battery will perform without issues. A poorly-maintained battery may have a shorter lifespan or lead to breakdowns on the road. 

Maintaining a truck battery is a necessary part of a maintenance routine and is so simple that truckers can do it themselves while on the road. Below are maintenance steps to carry out each month and every six months to improve battery life and fleet safety. 

What causes a commercial truck battery to fail? 

A commercial truck battery can fail for a variety of reasons. The top three most common are vibrations from the vehicle, improper charging and using the wrong battery. Yes, you read that right — step one to battery maintenance is ensuring that the battery is compatible with your vehicle. You also want to make sure the cables are securely attached to the battery terminals to prevent issues starting the truck. 

Beyond that, regular truck battery maintenance can help prevent issues on the road and extend truck battery life. 

How maintaining a truck battery can save you time and money

Maintaining a truck battery can reduce major hassles on the road. It can extend battery life and reduce replacement costs. It can also help to prevent battery failure, reducing the need for roadside assistance costs. The time it takes to maintain a battery every month will pay for itself through increased vehicle reliability, safety and cost efficiencies. 

9 steps to maintain a truck battery 

Follow these steps to maintain your truck battery and prevent failures or a shortened lifespan.  

Top off the water levels 

You should check the battery fluid each time you change the oil on the vehicle. If it’s low on water, you’ll need to top it off. To check the fluid level, unscrew the vent caps on top of the battery and look into each cell with a flashlight. If the fluid doesn’t cover the battery plates, it’s low. 

Use distilled water because minerals in tap and mineral water can affect battery performance. Fill with distilled water until the battery plates are covered and the water is just below the cell refill holes. Avoid adding too much water, which can cause additional issues. After closing the battery, be sure to wipe off any excess fluid. 

Check the battery acid level

The next step of truck battery maintenance is to check the battery acid level. Plan to do this every six months. When checking acid levels, check for stratification, in which electrolytes concentrate at the bottom of the battery and leave the top starved. You won’t be able to get a full charge on a stratified battery. You can see a video on checking battery acid levels here

Run a battery voltage test

Keeping a lead-acid battery that’s partially or fully discharged will significantly shorten its life. To keep a truck battery in top shape, test its battery voltage once a month. For this, you’ll need a voltmeter. A semitruck battery’s voltage is around 12.6-12.7 volts or more. Below 12.5 volts, you should recharge the battery right away. At 12.4 volts the battery is considered half charged, and at 12 volts it will be dead. 

Replace the battery when recommended

Replace the truck battery as often as recommended. Usually, this is about every four years, but the duration can vary by battery and vehicle. 

Routinely clean the battery

Did you know you can clean the outside of the battery with water and baking soda? To start, you’ll need to find the positive end of the battery, signified with a red cap. Then, disconnect the negative side by turning the bolt connecting the wires to the negative terminal counterclockwise, and lifting the wire up. Then do the same on the positive side. Don’t touch the wires to any part of the vehicle.

You can now use a one-to-one mixture of baking soda and water to scrub both battery terminals with a hard-bristled brush. This process can help remove rust and corrosion that inhibit battery performance. 

Check for erosion

Be sure to check for signs of rust and erosion. Then, after cleaning, you can protect the battery terminals from further erosion with terminal spray. The terminal spray is a special formula available at most auto parts stores. You hold the can about four inches from the terminal and spray until it’s coated. 

Reduce the number of short trips

Short trips drain the battery because it doesn’t have time to recoup the energy lost in starting the vehicle. If you only drive a short distance, the battery doesn’t fully recharge. If you do this regularly, you’re left with a partially charged battery and poor battery performance. 

For most truck batteries, this isn’t an issue, but you should be sure to drive the truck regularly for long distances to maintain a healthy, fully charged battery. 

Avoid extreme heat

Extreme heat and extreme cold can both affect battery performance.  If you can, park the vehicle in the shade to extend the battery life. Likewise, if you are in extreme cold temperatures, consider a battery heater to prevent damage from the cold. 

Don’t leave the truck idle for long periods of time

Idling a truck battery drains the battery and reduces performance over time. That’s because the engine cannot operate at peak temperature when you idle, leading to fuel that doesn’t combust completely. This action leaves a residue that can damage the exhaust system and battery over time. 

Protecting heavy-duty truck batteries

Heavy-duty truck batteries have a huge role in your fleet, which ideally goes unnoticed. However, like car battery maintenance, regularly checking for erosion and running a voltage test should become a regular part of truckers’ routines to extend the fleet’s battery lives. Additional steps like checking water and battery acid levels should take place with each oil change. By following the steps above, your batteries should serve your fleet without draining your wallet. 

For more information, check out the Texas government’s Vehicle Battery Safety Fact Sheet


What is the average life of a truck battery?

The average life of a truck battery is three to five years. Weather conditions, maintenance and use all affect the truck battery’s lifespan.

How do you know when your truck needs a new battery?

If your battery is more than three years old, it’s time to consider a new battery. ​​Signs that your battery needs replacing include dim headlights, a slow-starting motor heater or the vehicle not starting.

How much does a good truck battery cost?

A good truck battery could cost as little as $100 to $200, but it depends on the vehicle type, battery model and manufacturer. 

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