The car battery is probably one of the more frequent components you’ll change in a vehicle as it has a set lifespan — every 3 to 5 years. A weak battery is a common reason for engine stalling.
So, it makes sense to keep an eye on your battery, know what causes problems, and know how to fix those problems.
Let’s explore four typical battery issues:
1. You Have a Dead (or Undercharged) Battery
A dead battery is hard to miss.
You turn the ignition, and instead of a smooth crank, all you hear is a “click-click.” Then you notice the ominous red rectangle glow of the battery light that won’t blink out.
Or perhaps your battery isn’t quite dead (but is certainly weak.)
Your engine has trouble cranking, and the headlights are dimmer than usual at night.
Why It Happens…
- Age: Batteries typically last between 3-5 years, so if yours falls into that category, your battery probably has exhausted its lifespan.
- Leaving Headlights On: Another common cause of dead batteries is leaving the headlights on. Headlights eat up a lot of power, so they can quite easily discharge your battery.
- Faulty Alternator: If your alternator isn’t functioning well, it won’t properly charge your battery when you’re driving. You’ll be left with an undercharged and weak battery.
How to Fix…
- Jump-Start: To get your car moving, you could jump-start it (you’ll need another vehicle or a portable jump-starter for this). Drive around for about 20-30 minutes to charge the battery, and it should be fine.
- Use a Battery Charger: If you have one of these, you can skip the jump-start to get your car moving.
- Replace the Battery: If the battery was drained because the headlights were left on, you don’t necessarily have to replace it. However, if the battery is old, swapping it for a new one is probably a better option to prevent a repeat no-start.
- Replace the Alternator: If the problem persists and your battery is new, your alternator may be failing. In that case, you’ll need to replace the alternator.
2. Corrosion Has Invaded Your Battery
You have trouble starting your engine. You pop open the hood and notice some white or blueish powdery stuff on your battery terminals.
Yep, your battery is corroded.
Why It Happens…
Corrosion can arise from exposure to moisture, vented hydrogen gas, battery acid leakage, or a combination of these, to name a few causes. Corrosion creates more resistance in the battery’s circuit, disrupting the electrical current, leading to reduced performance and lifespan.
How to Fix…
Depending on how much corrosion there is, cleaning battery corrosion isn’t necessarily a tough task. You can use household items like a wire brush with baking soda and water to clear it. After that, apply a battery terminal protector spray.
Read our detailed guide on removing battery corrosion.
3. Your Battery Needs Fluids
If you have a flooded lead-acid battery (not one of the sealed variants), topping up your battery water at certain intervals is necessary. A battery low on fluids may take a long time to crank your engine. You might also notice dimmed headlights and your battery light flickering on.
Why It Happens…
As your battery recharges, electricity flows through the electrolyte. This process breaks down the water (H2O) in the electrolyte into its core elements—hydrogen (H2) and oxygen (O)—which are both gases. The gases are vented into the atmosphere (called ‘gassing’), and that’s how water is lost.
You’ll notice more battery water loss in high temperatures or if the battery is overcharged, as increased heat causes more water evaporation.
How to Fix…
Topping up your battery water level is easy. Open the vent cap and add distilled water just enough to cover the lead plates. This battery water article provides more detailed instructions.
If you’re losing more battery water than usual and it hasn’t been exceptionally hot, you might want to get a mechanic to check your charging system for overcharging issues.
4. Your Battery is Overcharged
The most obvious sign of battery overcharging is if the battery is swollen or leaking. You may also notice that the battery is unusually hot, or your battery water level keeps dropping. Sometimes, there’s corrosion from excessive gas venting.
If you do a voltage test, an overcharged battery will likely show voltages significantly higher than the normal 12.6V with the engine off.
Why It Happens…
The most common cause of battery overcharging is probably a bad voltage regulator or alternator. These parts work together, so you’ll have battery problems if one is faulty.
Another possible cause is a malfunctioning battery charger. Overcharging could also happen if you leave the battery charging too long or use the wrong battery charger for your battery type.
How to Fix…
If you catch the issue early—such as frequent water loss—but the battery isn’t deformed, you may still be able to use the battery. However, if your battery is swollen or leaking, replace it. Using a damaged battery is extremely dangerous.
The next step is to fix the root cause, likely a faulty alternator or voltage regulator.
If fixing your battery ever feels overwhelming, help is just a few clicks away.
Contact AutoNation Mobile Service, and our expert technicians will drop by to lend a hand.