Charging advice required

[Lantana frs]

Originally Posted by renfield90

I found the problem.

OEM batteries are notoriously poor quality. I got 2.5 years out of mine which was pretty good considering my climate.

Recommend you get the next battery from your local parts store, and hook it up overnight to an external charger 2x per year. I have made a cheapo parts store battery last 6+ years that way.

I didn't drive my car for over a year but had it hooked up to a battery tender. I swear by those things. Oem battery still going strong.

[humfrz]

Originally Posted by Ultramaroon

I blame this on manufacturers cheaping out on key components. I got sick of replacing the alternator on my Eclipse every time I left the headlights on. On my third one, I replaced the puny little internal regulator with a beefy F-150 external one. Never learned to shut off my lights but that alternator kept right on charging.

Well, now, THAT brought on a chuckle .....


humfrz

[s2kbobby]

Originally Posted by steve99

Do you have any non standard accessories, ie media system, dash cams , alarms etc.

devices plugged into obd port ?

None of the above. The car is stock.

I charged the battery overnight before taking it in to test the charging system.

[s2kbobby]

Originally Posted by renfield90

OEM batteries are notoriously poor quality. I got 2.5 years out of mine which was pretty good considering my climate.

Amen! The battery I bought from Subaru a year ago had a 2" plastic spacer at the bottom to keep it the same height as the original. I would have liked to see that 2" occupied by plates and electrolyte.

[s2kbobby]

Originally Posted by humfrz

As mentioned before, have you cleaned the battery posts/cable connectors..??

They may "look" clean, but still have a layer of varnish that could prevent a good contact.
humfrz

Yup! The posts and connectors are nice and clean.
Years ago, battery posts would obviously corrode with grey gunk. Not so much now and a poor connection is much less obvious.
Even my 14 year old Honda has clean terminals. I am not sure what changed. Perhaps the composition of the posts or connectors has been changed to reduce the dielectric effect.

[humfrz]

Originally Posted by s2kbobby

Yup! The posts and connectors are nice and clean.
Years ago, battery posts would obviously corrode with grey gunk. Not so much now and a poor connection is much less obvious.
Even my 14 year old Honda has clean terminals. I am not sure what changed. Perhaps the composition of the posts or connectors has been changed to reduce the dielectric effect.

Captain Obvious here ...... you have checked the electrolyte level ......


humfrz

[s2kbobby]

Indeed! I didn't. The battery is less than a year old and I have to remove the strap to access the one large cap that covers the inspection holes. That's my next job. . . .

BTW it has had no issues since I gave the battery a full charge.

There has to be a significant parasitic current draw somewhere that could discharge the battery overnight. Intermittent at that.

[churchx]

Most common parasitic current draw type big enough to drain batteries overnight are forgotten left on lights

[guybo]

If you got the battery tested, you don't have to check the electrolytes, that problem would be apprarent with the test (it'd cause a failed batt test)

Are you sure the battery is getting drained? When it won't start, will it turn over slowly but won't start or will it click once or many clicks? Will it do nothing? What's the voltage when it won't start? I'm beginning to think that this is a starter issue

[Ultramaroon]

Originally Posted by churchx

Most common parasitic current draw type big enough to drain batteries overnight are forgotten left on lights

[s2kbobby]

Originally Posted by churchx

Most common parasitic current draw type big enough to drain batteries overnight are forgotten left on lights

I agree for most other cars. The BRZ has an "Auto" feature that turns on lights at dusk and turns them off when it is light. It also leaves the lights on for 30 seconds after the car is stopped.

From the manual:
"The light switch is in AUTO, the headlights and tail lights turn off 30 seconds
after a door is opened and closed if the push-button ignition switch is turned
off." -- The push button ignition switch refers to the keyless entry models.

Additionally from the manual:
"Battery-saving function-
In the following conditions, the headlights and the other remaining lights will
go off automatically after 20 minutes in order to prevent the vehicle battery
from being discharged."
There are a few situations that will cancel this battery-saving function however none of them apply to my parking situation.

So you see, the drain on the battery is not likely to be head light related unless there is something wrong with the in-car computer.

[s2kbobby]

Originally Posted by guybo

Are you sure the battery is getting drained? When it won't start, will it turn over slowly but won't start or will it click once or many clicks? Will it do nothing? What's the voltage when it won't start? I'm beginning to think that this is a starter issue

When it won't start it will turn over slowly and immediately stop. Subsequent attempts to start result in an even shorter turn over or simply dimmed lights as the starter engages.
No I haven't checked the battery voltage.

[s2kbobby]

I appreciate all of the feedback however I believe I will have to simply live with this until I can come up with a common set of circumstances that appear to contribute to the dead battery problem.
Taking it to the dealer will simply cost $100 for nothing, unless I can replicate the issue.

[Tcoat]

Originally Posted by s2kbobby

I appreciate all of the feedback however I believe I will have to simply live with this until I can come up with a common set of circumstances that appear to contribute to the dead battery problem.
Taking it to the dealer will simply cost $100 for nothing, unless I can replicate the issue.

It is odd that an easy 8 out of 10 battery issues reported on this forum are with BRZs. I have watched this topic closely and found that reported issues with the FRS are rare. I believe they have the same stock battery so there must be something about the BRZ features that are causing the issue. Something seems be causing a parasitic draw but I have no clue what it could be.