Subaru dead battery

[Donald]

The battery in the Forester was 4 volts this morning but the vehicle ran fine the day before. Did not see anything left on. The headlights on the stalk were left on but go off when the key was removed. So I doubt that was it since it's often left on.

Charged battery and tested on Solar battery tester and the CCA where 405, the rating is 390.

Anyway this happened once a year ago and we never figured it out, car worked fine after battery was charged.

 

[ThomasJagGuy]

Interesting. My 2010 Genesis 3.8 sedan did the same thing a few weeks ago. It was a cold night (30's) and next morning the doors didn't unlock when the button was pressed on the door handle. Key fob was inoperative as well. After jumping it off and letting it run for 10 minutes to charge it seemed it might be OK. I had removed and inspected the terminals for corrosion and didn't find any. Due to the age of 6 years I considered myself lucky to get that much life from the battery and so I went straight away and replaced it. In such cases I always check for unseen lights that stay on (in the trunk, glove box, etc). Found none of those in my case.

My vote is if the battery is over 4 years old and starts acting wonky I replace it.

 

[wrcsixeight]

If it happens again, and if you have an IR Temperature gun, try to find something that is warmer than the parts surrounding it.

Even the fuse block, if the gun is placed close to each individual fuse, should find one warmer than than others, so you can narrow down the circuit and parasitic draw device.

 

[Donald]

Battery is < 2 years old and tests fine with Solar conductive battery tester (after charging).

 

[Rand]

If you turn the lights off and on they wont auto shutoff.. my usual culprit is map light so easy to leave on.

 

[eljefino]

glovebox light?

 

[Nick1994]

I'd take it into the dealer.

Even my Buick, which I bought at an auction and had been sitting for months, has a 5-1/2 year old battery which is unheard of in Phoenix. It starts great. Was dead when I got it but I jumped it and it's been fine.

 

[ejes]

One of the things I've heard of on Subies is that if your car has keyless start, to make sure you don't leave a key fob within 10 feet of it or else the electrical system will not go into "deep sleep" mode. So if you park it in the garage and leave the key in it or close by, this can be a cause.

The other thing I've heard of is leaving an iPod plugged in to a usb port (or other device) can cause a parasitic drain on the Subies.

This is a pretty good parasitic draw video: https://www.youtube.com/watch?v=KF1gijj03_0

 

[LoneRanger]

Originally Posted By: wrcsixeight
If it happens again, and if you have an IR Temperature gun, try to find something that is warmer than the parts surrounding it.

Even the fuse block, if the gun is placed close to each individual fuse, should find one warmer than than others, so you can narrow down the circuit and parasitic draw device.



That is a very cool and ingenius tip, putting that one in the old memory banks. Thanks!

 

[Michael_P]

Modern day evaporative canisters particularly on Asian PZEV cars can run a battery down. Sometimes you'll hear a faint whirring sound while the car is off toward the fuel tank.

 

[Donald]

Charger was disconnected last night after it said fully charged.

Car started fine this morning. Did not find dome or similar light on.

 

[supton]

Battery in bad shape, but is good enough to crank? Yet dies with any light load, like a single light?

I had a thread about it last week, as I had left a door open on my truck, for a week plus. But it has enough brains to turn off the light after some period of time (hour?). Killed the battery just the same. Jumped and it's been fine since. It was 15F overnight, just checked; 12.29V (battery between 15 and 30F I'd guess). Cranked ok, but I still think the battery is marginal. It certainly can't handle a minor trickle load, by the sounds of it.

 

[H2GURU]

Sorry but many complaints of weak or dead batteries in new Subies. They apparently cheapened out on the battery. Really, for your location you could see multiple below 0* days and 390 CCA won't cut it.You need a new battery and people are going with 640 CCA size now.

 

[JTK]

Soon after my SIL took delivery of her 2016 Forester 6spd, she was left stranded twice due to the battery being so weak. Dealer replaced the battery and she hasn't had the problem since.