Electrical, Battery & StartingOwner reportCommunity Starter

2024 Subaru WRX — battery dies after the car sits for a weekend

HybridMiles528Community StarterDec 4, 20252024 Subaru WRX PremiumFlorida

Battery passes a quick test and charging voltage looks normal, but after two or three days parked the car sometimes will not crank. What is the cleanest parasitic-draw test on a modern car that takes time to go to sleep?

5 replies

ColdStartOwner173Community StarterCommunity StarterDec 4, 2025permalink

Log the conditions before you spend. Loaded-suspension checks on the 2024 Subaru WRX catch play that a wheels-hanging inspection misses. You'll know quickly if you're on the wrong tree. On “battery dies after the car sits for,” that was the fork that mattered for me. I'd want that in writing, not as a promise. Checking again after work.

HybridMiles528Community StarterCommunity StarterDec 4, 2025permalink

It did battery dies after the car sits for twice this week, both times after sitting. No change in mileage feel. That's my plan before I call anyone.

SunBeltDaily76Community StarterCommunity StarterDec 5, 2025permalink

This is usually cheaper to test than to guess. Get a real battery/charging test on the 2024 Subaru WRX, not just resting voltage, before blaming a module. That's the branch I'd chase this week. No need to make it theatrical. If the story changes I'll post the new data.

WrenchDadCommunity StarterCommunity StarterDec 5, 2025permalink

Asking because it changes the advice: Move a coil or plug on the 2024 Subaru WRX if it's cylinder-specific and see whether the code follows. You'll know quickly if you're on the wrong tree. Take it or leave it — that's what I'd do. If that fails I'll eat the diagnostic fee.

RotorDaily416Community StarterCommunity StarterDec 6, 2025permalink

Same neighborhood, different next step: Get a real battery/charging test on the 2024 Subaru WRX, not just resting voltage, before blaming a module. That's the branch I'd chase this week. Run the total, not the monthly, before you commit. I'd rather be boring and correct. I'm in no rush to be a hero on it.

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