If you don’t drive your car for several years, it shouldn’t be much of a surprise when you try to turn it on, and it won’t start. It’s normal for car batteries to lose their charge over time. But sadly, driving your car regularly still doesn’t guarantee your battery won’t ever die.

So if your car battery dies, and the reason isn’t obvious, do you just have to buy a new battery? Usually, it depends on what caused your battery to die in the first place. There are some things that can drain your battery that you might never even thought of. Here are a few according to NADA Guides.

Loose battery connection

If your battery is disconnected, your car definitely won’t start. But as long as you don’t do it yourself, that’s pretty rare. What’s much more common is for the connectors to be loose. When that happens, your car may just shut off, or the engine may sound like it’s suddenly running poorly.

The good news is, the fix is pretty simple. You just have to tighten the connection. But corrosion can also cause a similar problem. If that’s the case, just clean that off. Odds are, your car will start right up.

Faulty alternator

If you’re not already aware, your car’s battery normally gets recharged by the engine. As you can imagine, if it didn’t, you’d need a much bigger battery to travel long distances. The part that recharges the battery is called an alternator. If that dies, you’re going to have to replace it. A jumpstart will get you moving temporarily, but before you know it, you’ll have a dead battery again.

Sometimes, though, the alternator causes problems without completely dying. One of the pieces inside called a diode may just need to be replaced. That’s obviously not ideal, but it’s better than having to buy a brand new alternator.

Electrical gremlins

In theory, if you’ve got the key in your hand, your car should be completely off. Well, except for the clock and an alarm system if you have it. Occasionally, though, things go wrong, and something doesn’t turn off like it’s supposed to. That then drains the battery just like it would if you left the lights on all night.

While it’s possible to fix the previous issues on your own (with the alternator definitely being more complicated than tightening a connector), if you have phantom electrical issues, it’s probably time to bring in a professional. They’ll be much more likely to figure out what’s wrong with your car. Perhaps more importantly, they’re also less likely to make a mistake that causes bigger, more expensive problems.

Fixing a car battery problem

Whether it’s leaving your lights on or having a connector, some battery issues are easy to fix and even easier to prevent in the future. Just to be safe, we recommend carrying a portable jump starter or at least your own jumper cables, as well as a basic tool kit. In addition to being able to fix your own car’s issues, you may also be able to help another stranded motorist.

More serious problems such as the faulty alternator and the glitching electrical system, are usually better addressed by a mechanic. It will be more expensive, but professionals can often diagnose the problem much faster than an amateur. And especially if it’s something that requires specialized tools, trying to fix things yourself could end up being more expensive.