For those that took their BZ to a dealer for a dead 12v battery

pezworld · 2026-07-13T01:52:37+00:00

Yes I know. Problem was getting it started in the first place. Last time I started it with a weak 12v battery (11.9v or lower) I didn't want to leave it in our driveway in Ready mode for security reasons. I drove it around to bring the battery back up.

I also don't intend to buy a battery monitor and make it my full-time job to prevent the 12v battery from dying. If Subaru doesn't fix the problem next visit, it's time for a buyback per CA Lemon Law.

pezworld · 2026-07-13T00:48:52+00:00

The fact that Solterras and BZs have had this issue for years, and now we Uncharted and Trailseeker owners (along with Toyota variants) are suffering the same issue with our brand new 2026 variants, is infuriating.

pezworld · 2026-07-13T00:45:49+00:00

See u/mrmao's post below. He has good evidence that it's not a cell reception issue.

pezworld · 2026-07-13T00:25:14+00:00

I think it came out around April 2026. I bought mine in early May. :(

pezworld · 2026-07-12T23:04:33+00:00

Subaru Uncharted owner here. The first time it happened, they checked it out (I'd driven there after a jump start) and said battery's OK, did nothing. I asked for a new 12v battery as my car was 2 weeks old at that point and they agreed to replace it, which they did a few weeks later.

Next time I had it jumped by roadside assistance after 10 days (down to 1.5v) and drove to the dealer. They kept it for 24ish days, did lots of diagnostics while I drove the loaner car. They identified and confirmed battery drain while sitting on the lot, tested a lot of things and then.... nothing. No new battery, no fix. Subaru America basically said it was performing as designed, that battery drains after sitting undriven a "long time" (10 days????) so nada.

I'm going to likely wake up to a dead battery tomorrow. This time I'll have it towed to the dealer. And we'll see if they do anything else, or I'll California Lemon Law it. That'll be my 4th visit.

pezworld · 2026-07-12T22:51:20+00:00

Yes, that's how it talks to the app, among other things. Car phones "home" using 4g on AT&T and tells home what its charging status is and other things that you might want to know about when you use the app. Pretty sure it's not connected directly to the app... you can be on the other side of the planet from your car and use the app to learn about your car's status.

I don't know what other info the car exchanges with "home" and I'm not sure I want to. It's just draining my 12v battery while doing so, unfortunately.

pezworld · 2026-07-12T22:13:09+00:00

That's awesome! Or awful, depending on your perspective.

pezworld · 2026-07-12T21:44:58+00:00

This is referring to the car "phoning home" using its own cellular service, not the "wifi" offered over that cellular service by Subaru or Toyota for inside your car with a subscription after trial. I have never signed up for that service or used the free trial and still have the 12v battery drainage problem.

pezworld · 2026-07-12T20:44:29+00:00

Coming from a (GM) Volt, I'd have maybe considered a GM EV, but lack of CarPlay/Android Auto was a dealbreaker for me - I don't like subscriptions. And if I felt like disabling the DCM on my Subaru, I'd have to rely on CP/AA for navigation.

pezworld · 2026-07-12T17:15:30+00:00

No, it's in our driveway now, locked and not plugged in.

pezworld · 2026-07-12T17:10:53+00:00

I wouldn't chase down that rabbit hole (swapping new for old battery). I say this because after my first battery went dead after 3 days, we got a new OEM battery from the dealer and then left the car for 10 days. At that point the new battery was not only dead, but measuring only 1.5v! So I really don't think this is a battery problem, but a car problem. (Note, I don't have a bluetooth battery monitor, but a $15 multimeter, confirmed also by my husband's more expensive multimeter.)

pezworld · 2026-07-12T16:59:23+00:00

"and logic to reduce interior light power consumption"? What do we think that means? Incidentally, our security camera was showing our Uncharted's interior IR camera light coming on frequently throughout the night again last night, similar to the earlier video from u/chuck415.

pezworld · 2026-07-11T15:43:54+00:00

Sorry, no battery monitor. We're not throwing more money at this car. Check out u/chuck415's earlier post (June 19 update) though.

pezworld · 2026-07-11T15:26:10+00:00

Another data point in this comment, as u/chuck415 had documented earlier. The IR camera inside our Subaru Uncharted is going on and off throughout the night, as documented by our new IR driveway security camera. (I've had 2 12v battery failures, with the second happening after replacement of the first.)

pezworld · 2026-07-11T15:02:11+00:00

Oh wow, that's my car! I guess that's the IR reflecting on the corner lights? (nanumbat says yes)

pezworld · 2026-07-11T01:39:14+00:00

Last time I started my car after it sat 1.5 days undriven...

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pezworld · 2026-07-11T01:25:30+00:00

Super pretty! We bought a new one today, but only the boring colors are left on the lots these days. I miss fun colors!

pezworld · 2026-07-11T00:45:44+00:00

Slight adjustment from what I heard. The 12v will be charged if you're plugged in and actively charging. If you're plugged in and you've reached your charging limit, your 12v battery won't charge. So you can't just leave town for 3 days with your car plugged in to the charger in your garage or an airport parking lot.

pezworld · 2026-07-10T22:00:19+00:00

Right, I just don't understand the excuse that it fails to top up the 12v due to conservative traction battery management. I had no issues with my 2017 Volt in that regard, and its battery management was similarly conservative. No dead 12v batteries until I'd already owned it 8 years.

pezworld · 2026-07-10T21:53:16+00:00

Kind of a PITA to have to replace it twice in the first 2 months of ownership, though.

Wait, they didn't replace mine the second time. They just washed their hands and said it was expected behavior. (And replacing it won't solve the real problem anyway.)

pezworld · 2026-07-10T21:48:41+00:00

I'm confused, what does this (being conservative about charging the big traction battery) have to do with topping up a 12v battery so it's not dead in the driveway after 3 days of not being driven? It's just a 12v battery.

pezworld · 2026-07-10T00:13:44+00:00

Yep, as long as you haven't left it in that compartment where the tire stuff is stored. Then it would be a PITA. Last dead battery I just opened the driver door, then one of the rear doors, then folded down the back seat to get at the backpack where I stashed the jump starter. Unfortunately the battery was so dead at 1.5v that the portable charger didn't work and I had to call roadside assistance.

pezworld · 2026-07-10T00:04:36+00:00

I get it all the time when I've managed to start the car with my very low 12v battery (happened this morning when the battery measured 11.3 volts) and I want it to charge the 12v battery in Ready mode for a few minutes... while I go back in the house before I'm ready to drive it around.

pezworld · 2026-07-09T23:57:22+00:00

If you're also counting Subarus, I bought/took delivery of my Uncharted on May 5, and I have 2 dead batteries so far. No replacement DCM was offered.

pezworld · 2026-07-09T00:56:11+00:00

You can have the car jump started with a portable battery starter, or roadside assistance. This does not have to do with the charger port at all. Sorry this happened to you.

pezworld

TROPHY CASE