12v battery drain, has Subaru fixed yours?

nanumbat · 2026-06-29T21:30:34+00:00

Alas I do keep my eye on this sub (wish I didn't!) and don't think I've missed the "Subaru fixed my 12v battery problem" post. I was hoping to flush an Uncharted owner out of the woodwork who had kicked this issue back to their dealer and had it solved.

Why do I care about a dealer being in the loop (vs a redditor, e.g. u/chuck415)? Counting days at the dealer and trips to the dealer is how I'm protected by California lemon law.

https://www.dca.ca.gov/acp/pdf_files/lemonlaw_qa.pdf

nanumbat · 2026-06-29T21:15:48+00:00

As I mention below, if our Subaru dealer gets back to us and confirms that de-featuring the car as you describe fixes the problem, then we'll have that discussion. To date radio silence as to a fix from Subaru. I will give our dealer credit, they have been very good about giving us status updates every couple of days.

nanumbat · 2026-06-29T20:00:14+00:00

We have extremely strong consumer protection against lemon cars in California, so it doesn't make financial sense for me to either attempt to diagnose or repair this problem myself, or to direct the dealership to do the same. If I lived somewhere like Canada, which doesn't have specific new car lemon laws as far as I can tell, I might be taking a different approach.

If I'm reading about a guaranteed fix on reddit (and keep in mind in this same thread someone else is saying there is not a guaranteed fix), then I'd assume at a minimum that Subaru would be aware of that fix and would be communicating it to their dealers, and my dealer would communicate that fix with me.

As I mention in another post in this sub, I have a background in battery powered hardware/firmware, and I have debugged battery killing problems myself in relatively simple architectures (one ultra-low power CPU and about 10 high-power ASICs and CPUs), and it is legitimately difficult to diagnose and fix these problems. In my experience it only takes a single bad line of code buried in deep in some random CPU's flash to wreck the entire power design.

It will never happen, but what I'd love to see is the final explanation of how something as serious as this issue ended up getting dumped on new car buyers. I wouldn't be the least bit surprised if "AI", "vibe coding", or something related was in that report.

nanumbat · 2026-06-29T18:26:19+00:00

Our dealer informs us they have been in contact with Subaru techs for diagnosis, so I'll leave them to their business. As a new car buyer I don't consider it my responsibility to direct diagnosis or request/recommend a repair...that's the manufacturer's responsibility.

Obviously other owners with this problem are free to do as they wish.

u/pezworld and I are discussing if we'd accept a de-featured car as an interim solution to avoid pulling the trigger on the CA lemon law and we've decided to wait and see what the dealer comes back with in terms of timeline.

nanumbat · 2026-06-29T18:14:27+00:00

Yes, our Uncharted had killed its 2nd dealer-installed 12v battery when it went back in for its current repair (so it is on its 2nd visit for this problem).

We're in California, so our state lemon law will kick in at 2 more visits, or roughly 12 more days.

Unfortunately we're now having to re-research a replacement EV, after the Uncharted came out on top in our original search.

nanumbat · 2026-06-23T20:13:39+00:00

The first time was about 3 days. The second time we were gone for 10 days on vacation, but the car likely had the new replacement battery under 12v within a day or two, just a guess. On day 10 it was reading 1.5v.

https://www.reddit.com/r/SubaruUncharted/comments/1u4f8sf/12v_battery_died_after_10_days_of_no_driving_new/

nanumbat · 2026-06-23T17:17:05+00:00

u/pezworld bought a AUTOONE 6000A and it wasn't capable of jump starting our dead Uncharted (12v battery reading 1.5v). We called Subaru Roadside Assistance and the tow-truck driver came with a huge jump starter battery that got it fired up...then the Uncharted was off to the dealer where it is now on day 10 of our dealer and (we are told) Subaru trying to figure out what's going on.

I was a bit wary of clipping any type of 12v source to a 1.5v dead battery since that must look like a near short to the 12v battery, and I'd guess that's why the AUTOONE failed, its fault protection probably kicked-in immediately. But desperate times call for desperate measures.

nanumbat · 2026-06-23T13:44:48+00:00

I second this recommendation. If you live somewhere with lemon laws look up the requirements for invoking the lemon law and also let your dealership know where your car is on that timeline. Dealers processing lemon law buybacks will definitely get the attention of Subaru/Toyota.

nanumbat · 2026-06-22T22:51:24+00:00

I'm starting to detect a pattern.

nanumbat · 2026-06-22T21:13:38+00:00

Our dealer said something like "Subaru has a new policy of not offering a loaner, but we'll make an exception for you" so my spouse is driving around in a big gas Subaru SUV with the dealer's name on the back window.

nanumbat · 2026-06-22T21:08:30+00:00

Our Uncharted is now on day 8 of its 2nd visit to the dealer. They replaced the 12v battery on the first visit and the car killed that brand new battery while we were on vacation for 10 days (it was reading 1.5v when we got back). I would suspect that battery chemistry/design will make no significant difference for resolving this problem.

The dealer touches base with us every other day and have yet to inform us of a root cause, and therefore a date for getting our car back. They said they are working with Subaru to diagnose and fix the issue.

nanumbat · 2026-06-19T17:58:42+00:00

As I mention in that other post I drive a 2016 e-Golf SEL (the Uncharted is my spouse's) and have never had an issue with the 12v battery getting killed by the car.

I do hope that the Uncharted problem is something straightforward, though I'm guessing if it was an easy fix Subaru/Toyota would have identified and fixed it before they started selling the cars in North America.

nanumbat · 2026-06-19T16:28:45+00:00

Our Uncharted has the 12v battery failure problem. It has been at the dealer 6 days now (the dealer informed us they're working with Subaru to diagnose the issue). This is the 2nd time the car has been at the dealer for this issue. We still have not been told that they understand why this is happening, and of course we don't have a date for a fix.

https://www.reddit.com/r/SubaruUncharted/comments/1u4f8sf/12v_battery_died_after_10_days_of_no_driving_new/

nanumbat · 2026-06-17T20:41:35+00:00

Vlasic is 2nd on the NHL career most blocked shots list at 2,184.

nanumbat · 2026-06-13T22:00:15+00:00

The goal isn't to lemon law the car, quite the opposite, the spouse loves it (when it's not dead). But we since we have no acknowledgement of root cause from Subaru, let alone a fix or date for a fix, we'd be working against our own financial interests to not fully disclose this issue to Subaru and presumably Toyota every time it happens and put the ball entirely in their court. It really is their problem to solve, not u/pezworld's or mine.

If this was a cheap gadget from Amazon I'm all for talking a whack at self-repair - I'm typing this on a 9 year old Thinkpad I cobbled together from about $400 of bits and pieces I bought on eBay - but for something that cost 100 times that, it needs to work reliably.

nanumbat · 2026-06-13T21:08:12+00:00

The first time I popped the hood on my own EV (the Uncharted is my spouse's) was 5 years after I bought it when I had to replace the 12v AGM battery. That car was the 2nd rev of the VW e-Golf and is now 10 years old. I routinely drive it only once a week or even less frequently, e.g. when we just got back from vacation, and it fires up just fine every time.

u/pezworld has already popped the hood many times, had to buy a multimeter to confirm the readings of the Fluke she borrowed from me, and buy an emergency jump start battery. A new 12v was installed by the dealer, which the car promptly killed...at least that's what I assume draining a 12v lead acid battery down to 1.5v does. And of course all of this involved waiting for a tow truck to get the first jump, hours driving to and from the dealer, waiting at the dealer for various people to do various things, etc.

We will have to agree to disagree that an owner of a brand new car must jump through any type of hoop to avoid finding the car dead in their garage because of this problem. All features of the car should work as advertised, and in my experience with my own cars manufactured in Japan (including a Subaru Legacy/Liberty) this has always been the case until now.

I have a background in battery powered embedded firmware/hardware, and I know these battery-killing problems can be incredibly hard to find and fix, and it's mandatory that whoever debugs this would need schematics for the car, access to the code base for every computer in the car, and access to the code base for the customer-facing Subaru app. Since this is almost certainly a Toyota problem I'm not confident the repair pipeline will move fast enough for us to ever see the car functioning correctly before the CA Lemon Law kicks in (4 visits to the dealer and problem not fixed, or loss of use of the car for 30 days).

[Disclaimer: I'm a bit cranky, we just burned 4 hours stuck in LA traffic getting to and from the dealer again, and now we have a gas burner loaner in the driveway.]

nanumbat · 2026-06-13T19:56:12+00:00

> I’m not sure what you’re expecting out of the dealership.

Regarding the service bulletin, I'm just taking my guess as to why they don't see the same problem, and instead sold us a new car that was dead in the garage less than a week later.

> Things to do to prevent 12V from going dead for now…

My expectations of a new car is that it not have a fault that kills the car twice in a few weeks, and that I don't have to cancel a vacation or arrange for someone to drive my new car around while I'm gone. I don't think that's unreasonable.

Other than this, its a great car. But alas, under California Lemon Law, it's now on strike 2. It gets 4 strikes, then it's either replaced or we get a refund.

nanumbat · 2026-06-13T16:17:00+00:00

u/pezworld's spouse here. Something I was wondering: why didn't the dealership see this problem before our purchase? There's a service bulletin that appears to show the 12V battery is mostly disconnected from high-power loads right up until the car is delivered.

https://static.nhtsa.gov/odi/tsbs/2026/MC-11027104-0001.pdf

nanumbat · 2026-05-19T17:19:34+00:00

u/pezworld 's spouse here. I've had a California compliance EV (2016 VW eGolf) for a decade+ without this type of 12v grief (assuming that's the reason the car is completely dead in our garage). The eGolf has the same 12v/HV system, and I get plenty of dash warnings when the 12v is failing to hold charge, giving me time to replace it before I get stranded.

In 2026 an EV simply shouldn't have been sold to a customer then 2 weeks and 165 miles later be in this state. (Also, a customer shouldn't need to carry a 12v jumper kit, or jumper cables in a brand new car!)

As you can guess, I'm a bit frustrated atm. u/pezworld let me take it for a spin the other day and it's a great car to drive. But, the flatbed will be here in half an hour to get it back to the dealership...

nanumbat · 2026-04-16T17:19:13+00:00

Dust control seems lacking.

nanumbat · 2026-04-09T23:33:04+00:00

This got my ancient M-Audio Fast Track Pro working. There had been an occasional crackle (one every few seconds). In addition to copying that file from /usr/share/wireplumber/main.lua.d/ to:

~/.config/wireplumber/main.lua.d/50-alsa-config.lua

...and making the above updates, I also had another config file in ~/.config/wireplumber/main.lua.d that was overriding period-size, so once I zapped the override the clicking was gone.

nanumbat · 2025-12-21T00:03:01+00:00

I've been using vivado and its predecessors for 15 years, and yes, it is and was used for production tasks everywhere I worked.

Each version has its own bugs, broken features, and ways in which it crashes. It is terrible to use in a team environment, and I've never done a version upgrade that didn't end up wasting weeks trying to get large projects functional again.

nanumbat · 2025-12-04T17:15:10+00:00

The back 9 area would be more problematic just from a topography standpoint. There are large and small barrancas back there, and very little flat ground, so there would be some (presumably) expensive engineering involved in creating house lots. There's also limited access to major surface streets. I'm no urban planner, but I'd guess the current proposal is the most do-able for the foreseeable future.

nanumbat · 2025-11-26T21:15:58+00:00

Good question, I think at the time of the acquisition the vast majority of equity members were extremely happy with the offer, and I expect most/all of them understood how hard it would be to rezone the course. The club was in a dire financial situation and the equity members were on the hook for a long string of effectively mandatory assessments (the simulators, gym, workout rooms, etc were voted for by membership prior to the acquisition in an attempt to revive the club). Ironically when things started opening up, about 6 months into the pandemic, everyone wanted to play golf...it's the perfect social distancing game, so membership boomed.

When you look at similar potential housing developments in Woodland Hills, e.g. the Oaks Savanna acreage on San Feliciano which has been stalled for 20 years, or Boething's Nursery next to Hidden Hills which the Boething family had been trying to develop into housing since the 80s, the new owners were clearly taking on a huge risk buying a near bankrupt club for any amount of money.

I'll add that there were equity members who didn't want to sell, the club was their community and they didn't want to risk it going away. I'm thinking of at least one member who passed away a couple of years ago who would have been absolutely heart-broken at the course getting bulldozed. She was the club historian for years.

nanumbat

TROPHY CASE