The top three causes of a flat car battery
Much like the gas cylinder for your BBQ, your car battery has a way of letting you down at the very worst times. You’ll only run out of gas when you’re putting on the snags, and your battery will only be flat when you’re trying to drive somewhere! Yep, a flat battery is a frustrating but common problem for vehicle owners everywhere. We all know what we need to do – get a jump start from a kind stranger or call NRMA for roadside assistance. What many of us don’t know is why it’s happened, and that puts us at risk of encountering the same problem again down the track! So today, we’re going to break down the top three causes of a flat car battery.
Top flat battery causes
#1 Lights left on
Whether it’s your headlights, an interior light from the boot or a door left slightly open, the lights in your car will drain the battery if left on while your vehicle is off. When you leave them on overnight, the car battery drains, and in the morning you’re left with a flat battery. Newer vehicles today come with an annoying but helpful warning tone that sounds if you leave your headlights on. So, you’re less likely to experience the frustration and inconvenience of a flat battery with a new car.
#2 Old battery
Car batteries don’t last forever. We (like most mechanics) recommend you get yours checked at least twice per year, and replaced every three to five years. Every time you start your car, your battery charges up the electrical components like the radio. It also holds energy to sound the alarm in the event of a break-in. If it doesn’t have enough charge to do that, the car won’t start. Old batteries become less effective at holding charge with time, which is why they’re a higher risk for going flat even if you don’t leave the lights on. If your headlights have become a bit duller than usual, your battery might be due for a replacement!
#3 Faulty or broken alternator
When a customer comes in and tells us ‘their car battery loses charge overnight’, and they didn’t leave any lights on, and it’s not an old battery, we have a pretty good idea what the cause is: the alternator.
The alternator is the part of the engine that keeps the battery charged while the vehicle is running, and helps the battery keep the electrical components – like windshield wipers and headlights – running. The battery uses the most energy when you first start your car. If you turn it off before the alternator has had a chance to recharge, you could find yourself with a weak or flat battery next time you get in. If you have a faulty alternator, you could find a problem with your car starting. In some cases, faulty alternators can even cause the battery to drain while the car is on.
