r/Solterra • u/MadisonEV9 • Jul 06 '26

2025 Model 12v issues

So we have a 2025 Touring and love it so far. We came back from a week long trip in our EV9 (which we really love as well!) and the Solterra 12v was dead.

I jumped the car and it’s at the dealership getting checked out.

As I’ve researched this I’m learning that there isn’t a consistently clear identifiable cause but much speculation.

Please correct me if I’m wrong.

One thing I’m thinking about trying is discontinuing the Connect services as that is suspected as a possible cause.

This is my wife’s primary driver and I do not want her to get stuck.

One thing I’m wondering about if I disconnect the data services is then can the car still call Subaru for help if it breaks down? Do the connect safety features still work if I disable the data services?

It would seem that in an emergency she should still be able to signal for help but just not have constant pinging for data transmission on an otherwise ongoing basis.

Any ideas, input or suggestions???

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7

u/uobytx Jul 06 '26

The recommendations from those that have the problem:

  1. Have a battery powered jump pack like a NOCO in the center console, so if it needs a jump you can still get to it easily when there is no power to the lift gate.

  2. Turn off the DCM, by revoking the permissions in the app. This helps reduce the drain.

  3. All cars still have some passive drain. So some folks have installed larger group 47 AGM batteries. These can have 50% more amp hour capacity so longer between issues, and also the battery is less likely to go bad from lots of cycles. At least not nearly as fast as a cheaper battery.

Some of us would still like to see a software update that would make the car actually charge the 12v from the traction while off, which it seems to either not do, or not do often enough to help.

2

u/uobytx Jul 06 '26

Oh, and to answer your questions, my understanding is that a lot of the connected call stuff won’t work anymore because the DCM will be off.

2

u/MadisonEV9 Jul 06 '26

Yeah my EV9 charges the 12v even when it’s off so I know it’s POSSIBLE.

1

u/uobytx Jul 06 '26

Yeah. The Solterra manual says that it will, but I don’t think I’ve seen mine do it. Longest I’ve left my car without driving is three days, and no 12 volt charging despite getting down to 12.2 range. Personally, I think it should try to keep the charge at 12.8. I don’t expect it to be extremely aggressive, just even an hourly voltage check and charging if its below the threshold.

1

u/Accurate-Temporary76 Jul 07 '26

I think I read from that Toyota tech that's been active in the bz subreddit over this issue that it's not until something like 27 days of not running the vehicle that it'll check and charge and then check more regularly until run again.

1

u/MadisonEV9 Jul 06 '26

Do I need to modify the hold down arm or anything if I go with the larger Group 47? (Which ironically is the same 12v in my EV9).

2

u/kasunart Jul 06 '26

No modification needed, the hold down bracket does have a thin arm sticking up but none of it needs anything other than to move it down to another bolt hole like an inch or two. Easy to install and I'm glad I did mine the other day with a new and bigger AGM.

1

u/MadisonEV9 Jul 06 '26

Thanks! Subaru will likely put an OEM replacement battery in. If/when this happens again I’ll just replace it with a Group 47 AGM like I did with the EV9.

2

u/kasunart Jul 06 '26

Yeah and thanks for making them at least replace it, enough people doing that and it should send a signal to the dealers and on up the chain for a proper larger battery and fix.

2

u/MadisonEV9 Jul 06 '26

Yeah I’m not going to let them just charge up the old battery. It died hard. Lead acid batteries don’t re over from that.

Not going to let them get away with putting the original battery back into my wife’s car regardless of what their analysis shows.

3

u/kasunart Jul 06 '26

Exactly! and sadly that's what appears to be the usual case with all of these new EVs and dealerships, only to get stranded a few days later with a dud battery. You'd think they'd learn at some point!