12V battery dead after 8 days at 71% charge

[Megaman0025]

It's a known issue for gen1, supposedly fixed in gen2. I suspect it is a design flaw; this guy presented a compelling case that excessive cycling and selection of an undersized lead acid battery is part of the issue. Some have posted better experience with the lithium 3rd party placements.

I’ll be honest, I would have purchased an R1T by now if it weren’t for this issue and Rivian firmly trying to block people from replacing it themselves. It’s not that hard. Holding onto my R2 reservation but will not buy until it seems clear this is no longer a problem. I can deal with a miriad of build quality issues - but one that continues to “brick” cars randomly throughout the year.

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[VSG]

I’ll be honest, I would have purchased an R1T by now if it weren’t for this issue and Rivian firmly trying to block people from replacing it themselves. It’s not that hard. Holding onto my R2 reservation but will not buy until it seems clear this is no longer a problem. I can deal with a miriad of build quality issues - but one that continues to “brick” cars randomly throughout the year.

Your loss - sounds like a really poor reason to not buy a Rivian. The two 12V batteries in my LE R1T are still going strong after more than 3 years - no problems whatsoever. Just because some people have problems doesn't mean that ALL people will have problems, or even that a majority of the people will have problems.

Rivian is NOT "firmly trying to block people from replacing it themselves". Many people have replaced their own 12V. Rivian made a tradeoff back when they were desperately trying to launch. Many late-stage design changes were leading to a smaller and smaller front trunk (compare Gen 1 with the concept vehicle shown in 2018). (Also, by the way, they still have this tension in the trunk space vs all the other things they need the space for - see how Gen 2 moved the battery but still has a smaller trunk. I expect the R2 will have an even smaller trunk proportionally...) If they used a standard car battery, that would have forced even more reduction in trunk space. So they used a two battery design and had the batteries custom made to fit - a custom made battery costs manufacturers about the same as an off-the-shelf one, so it makes sense to customize it to be ideal for their needs. But that means there really aren't any exact replacements out there. Maybe Rivian was hoping battery manufacturers would step up and mass-produce these, but I don't think the volume is compelling enough. Similar to the situation with the 21" tires.

Rivian is probably just as sick of 12V issues as everyone else. They most certainly don't want to waste time and money doing warranty repairs, and they have better things to do than force people to come into the service center for non-warranty battery replacement. Look at how they're trying to off-load tire rotations and tire service to tire chains - non-warranty battery replacement is not a high-profit or high-volume business for them, and once they push out the announced software change that allows the end-user to reset the battery management software they will be happy to get out of that business.

I expect the R2 will have a more conventional 12V battery so they won't have to deal with these things. Just like Gen 2 and the R2 have more conventional tire sizes.

 

[1car-nut]

It's a known issue for gen1, supposedly fixed in gen2. I suspect it is a design flaw; this guy presented a compelling case that excessive cycling and selection of an undersized lead acid battery is part of the issue. Some have posted better experience with the lithium 3rd party placements.

I experienced the "Replace 12V Battery" error on my 2026 R1S earlier today and it would not charge as well. After 5 hours and 4 calls I finally got ahold of someone at my local service center. They were not surpised to see the error on a 2026 model and even said they had a number of calls about dead batteries this morning due to the cold weather. They estimated a week to fix it due to the backup of work they have.

 

[Megaman0025]

Your loss - sounds like a really poor reason to not buy a Rivian. The two 12V batteries in my LE R1T are still going strong after more than 3 years - no problems whatsoever. Just because some people have problems doesn't mean that ALL people will have problems, or even that a majority of the people will have problems.

Rivian is NOT "firmly trying to block people from replacing it themselves". Many people have replaced their own 12V. Rivian made a tradeoff back when they were desperately trying to launch. Many late-stage design changes were leading to a smaller and smaller front trunk (compare Gen 1 with the concept vehicle shown in 2018). (Also, by the way, they still have this tension in the trunk space vs all the other things they need the space for - see how Gen 2 moved the battery but still has a smaller trunk. I expect the R2 will have an even smaller trunk proportionally...) If they used a standard car battery, that would have forced even more reduction in trunk space. So they used a two battery design and had the batteries custom made to fit - a custom made battery costs manufacturers about the same as an off-the-shelf one, so it makes sense to customize it to be ideal for their needs. But that means there really aren't any exact replacements out there. Maybe Rivian was hoping battery manufacturers would step up and mass-produce these, but I don't think the volume is compelling enough. Similar to the situation with the 21" tires.

Rivian is probably just as sick of 12V issues as everyone else. They most certainly don't want to waste time and money doing warranty repairs, and they have better things to do than force people to come into the service center for non-warranty battery replacement. Look at how they're trying to off-load tire rotations and tire service to tire chains - non-warranty battery replacement is not a high-profit or high-volume business for them, and once they push out the announced software change that allows the end-user to reset the battery management software they will be happy to get out of that business.

I expect the R2 will have a more conventional 12V battery so they won't have to deal with these things. Just like Gen 2 and the R2 have more conventional tire sizes.

Is there a known software update coming to allow users to do this easily?

 

[VSG]

Is there a known software update coming to allow users to do this easily?

Yes.

 

[COdogman]

It's not just Rivian who has 12v issues. It's basically all EV manufacturers.

You're Worrying About The Wrong EV Batteries
https://insideevs.com/news/752720/ev-12-volt-battery-problems/

 

[AlanP]

I experienced the "Replace 12V Battery" error on my 2026 R1S earlier today and it would not charge as well. After 5 hours and 4 calls I finally got ahold of someone at my local service center. They were not surpised to see the error on a 2026 model and even said they had a number of calls about dead batteries this morning due to the cold weather. They estimated a week to fix it due to the backup of work they have.

That’s a bit sad since it took the Mobile Tech 12 minutes to replace it. Then a few more minutes to plug in his laptop and reset the computer.

 

[sfvR1S]

I also have a 2023 R1S and when I took it to SC for the 7,500 mile service, they proactively swapped out the 12v battery.

Did you have your vehicle serviced at Rivian? If so, did they mention anything about the 12v replacement?

 

[Time2Roll]

It's not just Rivian who has 12v issues. It's basically all EV manufacturers.

You're Worrying About The Wrong EV Batteries
https://insideevs.com/news/752720/ev-12-volt-battery-problems/

Yes and it should have been easier. Lead-acid has too many issues for EV use. Need to go heated LFP.
But what do I know.

 

[AlanP]

Arrived home from an 8 day trip and 2023 R!S wouldn't wake. Was at 71% when I left. I've been on 15+ weeklong trips without a problem. SC says since it wasn't plugged in Rivian will not provide warranty, tow or rental car. Is this the new normal? Is it due to a recent OTA upgrade? I typically lose 1-2% daily at the most .

Here’s the end of the story. A Rivian Mobile Tech came out and replaced the battery in about 12 minutes. It took another 10 minutes to reboot the car and do diagnostics with his laptop.. The traction battery was still charged at 71%, the same as when I left for vacation. The tech was super helpful and Rivian could’ve saved me eight hours of aggravation trying to get the vehicle towed. I was a little surprised how tiny the battery is. Kind of the same size as a motorcycle battery.

 

[COdogman]

Yes and it should have been easier. Lead-acid has too many issues for EV use. Need to go heated LFP.
But what do I know.

Agree 100%. It’s bad enough it’s this common of an issue. It’s worse they designed it in such a way that we can’t service it ourselves. Personally I would rather Rivian solve this puzzle than focus on AI/ Autonomy, but what do I know?

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