Prolong Your Car Battery's Life

Top Tips To Keep Your Car Battery In Top Shape

Electric vehicles may not just yet be taking over the gasoline world, but the battery is still a big part of every gasoline vehicle and without a properly functioning battery you can be stranded in the middle of the road. 

The batteries primarily used in automotive applications are Flooded or Wet Cell Lead-Acid Battery and Sealed Lead-Acid Battery (SLA). SLA batteries are maintenance-free since the electrolyte is sealed in the battery container from the factory and do not require maintenance of the electrolyte levels. Although many modern vehicles employ the use of maintenance-free batteries, many vehicles still use wet batteries typically due to their cost-effectiveness.

How To Maintain A Car Battery In Good Condition?

Regardless of the type of battery your car has, it is still prone to failure if not kept properly. Even maintenance-free batteries need to be periodically tested and checked for optimal performance or the effects can be irreversible and will require a new battery. 

We have compiled a list of checks that you can perform and tips you can follow which will tell you the condition of your battery and what you can do to prolong its life. 

Clean The Battery Terminals

The battery terminals often get corroded and form a whitish-blue layer. This layer of rust forms a barrier and prevents the battery from being charged and restricts the flow of electricity to the system. This build-up will eventually cause the battery to fail which is why it must be cleaned regularly. Start by removing the cable from the negative battery terminal followed by the positive one. Create a 1:1 mix of baking soda and water and apply a thin layer on the terminals. Use a metal wire brush to rid the terminal surface of any rust residue. Once cleaned, wipe with a clean towel to remove any excess baking soda remnants. Finish by spraying the terminals with an anti-corrosion spray like WD-40. Use a battery brush to scrape the inside of cable terminals using the same baking soda solution and wipe off the excess. Reinsert the positive cable followed by the negative cable on the battery terminals. 

Check The Battery Electrolyte Level

Flooded batteries have a vent cap atop the battery housing which allows access to each battery cell. The fluid level in each cell must be checked every 6 to 12 months depending on the battery to ensure the electrolyte level is not low which can cause acid stratification. The fluid should be up to the maximum indicated level or simply above the battery plates. If low, then use distilled water or deionized water (tap water contains minerals which can alter the electrolyte solution and hence must not be used) to top off each cell to the required level. Do not overfill the cell and clean any spills before closing the vent cap. The vent cap must be closed tightly after use.

No-maintenance batteries do not have vent caps as they are sealed but most have a built-in hydrometer that can tell the state of the charge and condition of the battery through the charge indicator which is a circular glass sight. The colour of the dot indicates the battery charge state or condition. If bright green then the battery is charged; if dark green or just a darker shade that is not clearly visible, then it needs to be charged before testing and finally a yellow dot means the battery needs to be replaced. 

Check The Battery Condition

The battery condition is well stated in the voltage it holds after it has been charged. To check the battery voltage you can use a multimeter or perform a hydrometer test. The hydrometer test can only be done on wet cell batteries whereas the voltage reading can be taken on any battery. The advantage of the hydrometer test is that it tells you the condition of each cell in the battery whereas the voltage reading will be an average voltage across all cells and does not isolate the failing cell.

Before doing the test it is necessary that you manually charge the battery with a charger. After charging the battery, leave it in a warm dry room for several hours before taking a voltage reading. This will remove any surface charge (surface charge causes the battery to show a false voltage reading that is higher than its true state after having been charged recently) will have on the battery and you will get an accurate measure of the battery’s condition. 

  • Voltage Test: This test can be done with a multimeter or a battery tester. With the engine off, hook up the battery terminals to the multimeter or battery tester. Switch on the battery tester and follow the instructions to assess the battery voltage. If using the multimeter, then set it to 20 DC volts and take a reading by attaching the correct multimeter probes to the battery terminals. The voltage reading must be above 12.6v indicating a full charge on the battery. 
  • Hydrometer Test: Remove the vent caps from the battery and insert the pipe end of the hydrometer into the electrolyte solution. Slowly draw in the liquid by pressing the suction cup on top of the hydrometer. Jar out any air bubble by slightly tapping on the hydrometer and wait for the float to rest. A good cell must have a specific gravity of about 1.25 to 1.30. If lower than 1.25 then the battery may still function but will soon require replacement. Anything below 1.20 is considered a dead cell. Repeat the process on all other cells and record the reading for all. This can help you assess the condition of the battery and identify any dead cells. Always make sure to avoid direct contact with the electrolyte solution and wear protective gloves and eyewear for safety. It is necessary to keep in mind that temperature affects the hydrometer reading. (The tester is calibrated presuming the battery is at 80oF. Add .04 to every reading for an increase in 10 degrees above 80 and similarly subtract .04 for every 10 degrees below. Getting a cell reading that differs by 0.05 or more means the battery is defective and needs replacing)

Conduct A Battery Load Test

Oftentimes the battery can show ideal voltage after just having been charged but can slowly return to its discharged state in a few hours. This means an initial voltage reading would indicate the battery is fine but its charge holding capabilities are diminished. This is why it is important to carry out a battery load test that shows the true state of the battery and whether it can hold more charging cycles. These tests can be carried out with a battery load tester or electronic battery testers. 

  • Using A Battery Load tester: Connect the tester to the battery. You can see the initial voltage reading the battery has. Now flip the switch to test it under load and notice the dial move. if the reading is above 9.6v then the battery is fine. If it reaches 9v or below then it needs to be replaced. 
  • Using A Battery TesterElectronic battery testers are versatile tools that can be used to conduct various tests on the battery. They can assess the CCA or cold-cranking amps, check the charging system functionality, check the battery’s charge holding capability and its condition. Hook up a tester and select the test that you want to conduct. Follow the instructions to carry out the test and find out the results. A battery tester is a simple and useful tool to find various battery and vehicle charging system faults. 

Check The Condition Of The Charging System

The charging system is what supplies and charges the battery as the vehicle is running and ensures that the battery remains functional. If it fails, then the battery will be discharged very quickly and may even get over-discharged which will likely damage the battery beyond repair and require replacement. To check the working of the alternator and voltage regulator you can carry out a simple test using a multimeter. Attach the multimeter to the correct battery terminals (negative = black, positive = red). and set it to 20 DC volts. Take a voltage reading prior to switching on the engine and make note of it. Then start the engine and notice the reading on the multimeter goes up to above 14 volts. This indicates that the battery is receiving a charge from the alternator. A reading of 15v or above can indicate the voltage regulator is broken and reading of 13.5v or below can mean the alternator isn’t working properly or the battery is undercharged. Now shut off the engine and read the voltage again. If the voltage is higher than the noted reading, then the battery is able to hold a charge and the charging system is also properly functional.  

Don't Over-charge Or Over-discharge

An overcharged battery produces excess hydrogen and has a higher charge voltage. If it reaches above the gassing voltage which is about 14.3v for Lead Acid battery, then there is a risk of explosion if any spark is introduced. Over-discharging a battery, especially a flooded type, can cause irreversible damage. Therefore you must always make sure the battery voltage is within the optimal range for prolonged battery life and reduced risk of explosion. 

Recharging The Battery Regularly

If you have a vehicle that you do not use very often, the battery in that car will self-discharge or lose its state-of-charge over time. This will continue until the battery is completely dead. To prevent this, you must regularly drive the vehicle or use a battery charger to regularly recharge it. 

Avoid Short Trips

A lot of battery juice is consumed while starting the engine and during a short trip there isn’t sufficient time for the alternator to completely restore the battery’s charge. Always consider driving frequently but for extended periods to maintain battery charge. 

Maintaining Battery During Varied Climates

The winter can take its toll on the battery of the vehicle and prevent engine startup. It is advised to utilize an engine or battery heater or an insulation blanket around the battery during winter for optimal battery performance. Whereas during summer months, the heat from the engine and the sun can cause the electrolyte to evaporate rapidly in flooded type batteries which can reduce their performance. Regularly inspect the fluid levels and properly seal the battery caps to ensure long-lasting performance.

Inspect The Battery Tray

Make sure the battery hold-down is securely fastened and tight to avoid battery vibrations and fluid spillage. Excessive vibrations can cause the battery internals to degrade and the battery to fail. If the battery tray isn’t upright, the fluid can leak out, harming not only the battery but various engine components. Therefore, you must always inspect the battery tray and the hold-down. 

Inspect The Battery Cables

Make sure the battery cables are attached properly to the battery and the alternator. Oftentimes the battery dies not because of alternator failure but because the battery doesn’t receive power from the alternator through the cables as they are too loose or damaged. If your cables are extremely worn out, frayed and torn then be sure to replace them. 

Avoid Excess Power Draw

When the engine is off it is necessary to switch off all the electrical appliances so that no power is drawn from the battery. If the headlights, interior lights or even the radio is kept on through the night, the battery will rapidly discharge and can possibly be dead by the time you try to start your car.

Modern vehicle batteries are getting increasingly expensive to replace which means without proper care, you may have to replace the battery even before the manufacturer-recommended service life span. Hence, to avoid costly battery replacement costs and get the best out of the battery and charging system of your vehicle, be sure to maintain your battery in optimal condition using the pointers mentioned in this article. You can also look out for other obvious problems such as a loose or broken alternator belt, corroded or swollen cables, a dirty or wet battery top, corroded battery posts or a leaking or damaged battery case. If you are facing starting issues with your car then the problem may be beyond just the battery. Read on more about why your car won’t start and find a quick and easy solution


The state of charge of the battery will eventually decline and the battery will be dead if left uncharged for a long time. This can prevent vehicle startup and disrupt security systems. Most modern cars can go about 2 weeks to as long as a month without dying completely, but this depends on many factors such as the electrical load, weather conditions and engine type. To prevent the battery from dying, make sure you drive or charge the battery once every week or two.

Drive your car at highway speeds for a minimum of 30 minutes in order to charge a healthy but low charge battery completely. Idling the engine does not rev the alternator enough to charge the battery at full capacity so it is important to drive at higher speeds or rev above 1500 rpm. However, the time it takes to completely charge the battery can vary according to the condition and age of the battery, the electrical load experienced and most importantly how much charge the battery initially had.

If you are able to jump start your car on the dead battery then you can completely recharge it. If the battery voltage drops below 12 volts, then it is considered discharged. A battery with 12 volts can be recharged by the alternator itself, so driving for 30 minutes can recharge the battery properly. If the battery voltage is lower than 12v, then you need to use a battery charger to completely juice it up safely.

A healthy battery can lose its charge overtime due to many factors such as loose or corroded battery connections, high parasitic draw, failing charging system, greater electrical load than the alternator can provide, and extreme weather conditions.

To ensure safety and to prevent damaging electrical components, always disconnect the negative or the black terminal first followed by the positive or the red terminal. While reattaching, always connect the red terminal first and then the black one.

1. Disengage the battery terminals if in a secure garage. Note that this will stop security systems as well. However, this will eliminate parasitic draw. 2. Recharge the battery by driving the car weekly for at least 30 minutes or charge using a charger. 3. Get a portable jump starter which can help you start the car and charge the battery in case you are unable to crank the engine on battery power alone. 4. Avoid short trips with repeated stops and starts. This can drain more battery power than the alternator has time to replenish.

John Framigllia
Technical Writer
Our technical writer is known for simplifying automotive parts and services. Intuitive with various vehicles and manufacturers, he knows how to simplify complicated problems.