Why is my car dying so fast even with a 6-month-old battery?

Hi everyone! I’m having an issue that’s driving me nuts. I replaced my car battery about six months ago, and now my car dies almost every time I shut it off. I’ve been getting by with a portable jump box, but it’s frustrating.

I’m wondering what could be causing this besides the alternator. I’ve attached a picture of the battery, and it looks like it might be leaking? Any ideas or suggestions would be much appreciated!

Use a wire brush to clean your battery terminals and connectors. Sometimes it’s just bad connectivity. My neighbor had the same issue, and cleaning it up with dielectric grease saved the day.

Lilnim said:
Use a wire brush to clean your battery terminals and connectors. Sometimes it’s just bad connectivity. My neighbor had the same issue, and cleaning it up with dielectric grease saved the day.

Clean it up and take it to an auto parts store. They’ll usually check the battery and alternator for free. Maybe even show them the picture of what it looked like before cleaning.

What year is your car? I have a 2019 Outback, and my battery kept dying because of the Data Control Module (DCM). The dealership bypassed it under warranty and replaced the battery for free.

ToyoLeez said:
What year is your car? I have a 2019 Outback, and my battery kept dying because of the Data Control Module (DCM). The dealership bypassed it under warranty and replaced the battery for free.

That sounds like the problem.

ToyoLeez said:
What year is your car? I have a 2019 Outback, and my battery kept dying because of the Data Control Module (DCM). The dealership bypassed it under warranty and replaced the battery for free.

It’s a 2019, but I haven’t seen any recalls for this.

@Leighton
It’s not a recall, but there’s a warranty extension for the DCM issue. Check with your dealership or look at this link: https://www.reddit.com/r/WRX/s/fG2UX5lbxM

@Leighton
Even if it’s not a recall, they should fix it for free if the DCM is draining your battery. Definitely ask about it.

ToyoLeez said:
What year is your car? I have a 2019 Outback, and my battery kept dying because of the Data Control Module (DCM). The dealership bypassed it under warranty and replaced the battery for free.

Exactly this! I bought a used 2017 Impreza super cheap because the owner couldn’t figure out why the battery kept dying. Pulled the DCM fuse, and the problem was solved.

It might just be your battery cable connectors. Try replacing those before looking into anything more complicated.

vinic said:
It might just be your battery cable connectors. Try replacing those before looking into anything more complicated.

I had a similar issue with a leaking battery that drained too fast. Maybe you got a defective one?

Check if there’s a recall related to the Starlink system draining the battery. It’s a common issue.

Start with a new battery, especially if it’s under warranty. If it’s defective, it should be replaced for free. After that, check the alternator with a multimeter to ensure it’s charging properly.

Have the alternator checked. :white_check_mark:

Leaking? Are you sure the battery is only 6 months old?

Page said:
Leaking? Are you sure the battery is only 6 months old?

Not 100% sure it’s leaking, but the dark spots around the caps are concerning. The battery might be closer to a year old, but not more than that.

Take the battery to get tested. My son’s car had a similar issue, and it turned out to be a bad cell in the battery.

Buy a $5 battery terminal cleaning brush and clean the posts and cable connections. Use some connection grease and pads to protect it. While you’re at AutoZone, have them test your alternator too. It’s easy to replace if needed.

If your battery is from Costco, that might be the issue. Their Interstate batteries aren’t the same quality as those sold elsewhere, according to my Interstate rep.

My car does something similar. If I listen to the radio for 20–30 minutes with the car off, it won’t start. Might want to check how much draw your system has when idle.