12v Lead Acid Battery Replacement

[MidnightRivian]

I dropped off my vehicle for the same 12v battery message. I got one last year and now within 12 months I got another 12v battery message.

It sounds like Rivian will step up and cover it under 2yr replacement battery warranty even though I am out of the original 3yr / 36k battery mileage warranty by couple thousands miles.

I like the good news from Rivian that they will provide a service option where we clear the error code after the swap. I think down the road I might look at after market options but for now I hope this replacement lasts more than a year or two.

Rivian Developing Service Menu to Let Owners Handle Repairs Like 12V Battery Replacements

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[epowermarine]

I'm right in the middle of this 'Rivian Adventure' right now: Sept 22 delivery R1T dual battery at 42k miles. Have had zero 12v problems and always had minimal parasitic loss but I figured I'd go ahead and swap in some new ones before mine ultimately die an inconvenient death.

I’m in the EV business (electric boats actually) and feel comfortable doing this kind of thing. Bought a couple of 20ah AGM’s for the swap. Getting the correct hardware was a pain in the ass but Ohmmu sold me the lug adapters, now I think someone on this forum can also make them. Prior to installation I put the new batteries on a Victron charger to top them off and they behaved perfectly.

Fast forward to my current situation: Batteries were installed last weekend. Shortly after the first boot-up I get the ‘Replace 12v Battery’ error but the truck is operating fine. I do a hard reset and a RIDE ‘LV Battery Service’ (or whatever it’s called) but the error persists.

Needed to use the truck for my weekly trip so I drove 200 miles, charged overnight, and drove back 200 miles, followed by another overnight charge. My efficiency during these drives was exactly what it always is, and I’ve had no range loss since I made the swap.

Let it sleep for a while today, did another RIDE LV recalibration, plus another hard reset. Still greeted by the friendly ‘replace 12v battery’ error.

Side note: Rivian has called me a couple of times this week to schedule service. They go through their script and I try to convey my situation, but they are not getting it. The script doesn’t allow for this type of thing.

I’ll just live with it for a few days and see what happens. I don’t have ElectraFi setup but I’ll likely do that today. We all know that we need to/should be able to do this on our own, and it sounds like we are only a software update away from that happening, but actually when that fix comes nobody knows.

 

[mudito]

@epowermarine

There's a reset procedure that CAN NOT be done by a user yet. Wassym already committed to include a user-replacement procedure in the software soon. Will see when.

 

[ksujeff99]

I'm right in the middle of this 'Rivian Adventure' right now: Sept 22 delivery R1T dual battery at 42k miles. Have had zero 12v problems and always had minimal parasitic loss but I figured I'd go ahead and swap in some new ones before mine ultimately die an inconvenient death.

I’m in the EV business (electric boats actually) and feel comfortable doing this kind of thing. Bought a couple of 20ah AGM’s for the swap. Getting the correct hardware was a pain in the ass but Ohmmu sold me the lug adapters, now I think someone on this forum can also make them. Prior to installation I put the new batteries on a Victron charger to top them off and they behaved perfectly.

Fast forward to my current situation: Batteries were installed last weekend. Shortly after the first boot-up I get the ‘Replace 12v Battery’ error but the truck is operating fine. I do a hard reset and a RIDE ‘LV Battery Service’ (or whatever it’s called) but the error persists.

Needed to use the truck for my weekly trip so I drove 200 miles, charged overnight, and drove back 200 miles, followed by another overnight charge. My efficiency during these drives was exactly what it always is, and I’ve had no range loss since I made the swap.

Let it sleep for a while today, did another RIDE LV recalibration, plus another hard reset. Still greeted by the friendly ‘replace 12v battery’ error.

Side note: Rivian has called me a couple of times this week to schedule service. They go through their script and I try to convey my situation, but they are not getting it. The script doesn’t allow for this type of thing.

I’ll just live with it for a few days and see what happens. I don’t have ElectraFi setup but I’ll likely do that today. We all know that we need to/should be able to do this on our own, and it sounds like we are only a software update away from that happening, but actually when that fix comes nobody knows.

I went through this in March. I replaced my dual batteries with Ohmmu. It took me so many attempts to get the 12 error message to go away. I ended up putting both Ohmmu batteries on the charger, disconnected from the truck, and leaving the truck without power for overnight. I reconnected everything the next morning and finally the 12V error message went away.

Now fast forward to this morning, after the most recent Halloween update, and the 12V error message is back. I tried a hard reset but no change. The Ohmmu batteries are smart and let me monitor their voltages and current flow through the iPhone app. Everything looks good from this high level view but the truck is upset about something. I’m not sure what to do now. Like you, my truck runs perfectly, but just doesn’t go to sleep so its vampire drain is higher.

 

[SwampNut]

I went through this in March. I replaced my dual batteries with Ohmmu. It took me so many attempts to get the 12 error message to go away. I ended up putting both Ohmmu batteries on the charger, disconnected from the truck, and leaving the truck without power for overnight. I reconnected everything the next morning and finally the 12V error message went away.

Now fast forward to this morning, after the most recent Halloween update, and the 12V error message is back. I tried a hard reset but no change. The Ohmmu batteries are smart and let me monitor their voltages and current flow through the iPhone app. Everything looks good from this high level view but the truck is upset about something. I’m not sure what to do now. Like you, my truck runs perfectly, but just doesn’t go to sleep so its vampire drain is higher.

Have you asked Ohmmu if they know what to do?

 

[epowermarine]

I went through this in March. I replaced my dual batteries with Ohmmu. It took me so many attempts to get the 12 error message to go away. I ended up putting both Ohmmu batteries on the charger, disconnected from the truck, and leaving the truck without power for overnight. I reconnected everything the next morning and finally the 12V error message went away.

Now fast forward to this morning, after the most recent Halloween update, and the 12V error message is back. I tried a hard reset but no change. The Ohmmu batteries are smart and let me monitor their voltages and current flow through the iPhone app. Everything looks good from this high level view but the truck is upset about something. I’m not sure what to do now. Like you, my truck runs perfectly, but just doesn’t go to sleep so its vampire drain is higher.

Thanks for your detailed reply. Funny (not funny really) that the Halloween update set you back, I am waiting for it hoping that somehow it magically fixes my 12v battery error! That being said I don't know if I will receive it because of the error. I have Connect+ and usually get them pretty quickly but nothing yet. Good luck and please update us on your progress.

 

[Rivianero]

I also have a single Ohmmu in my 2023 gen 1 R1T. I bought my truck from salvage so am not covered by warranty.

Beginning in September, I started getting "12v Failure, tow vehicle" errors.

The first time was when driving on the freeway; it did allow me to continue driving for 2 miles to a safe stop, not allowing accelerating.The Ohmmu app showed voltage at 13.4v. It took a few reboots and performing battery service in the RIDE menu to clear everything and get home. I checked the battery connections to make sure nothing was loose or corroded.

The other 2 times happened when trying to start the car after parking. Similar Ohmmu voltage readings. Same resolution each time took 5 minutes. My theory is that a software update made the vehicle more guarded about 12v issues, and since the Ohmmu is never going to behave 100% like the stock AGM battery, those differences were causing false errors.

Yesterday, after having lunch out, I got a new error with no specific message. It showed the battery meter at bottom right of the driver display as a red capsule with an exclamation point. Still 52% charged, but would not let me drive. No text errors whatsoever. My usual resolution did not work and eventually the truck went into some sort of boot loop where it kept trying to reboot. Eventually it went completely dead. The Ohmmu application showed the battery level at 7v with Discharge turned off. I sourced a 12v battery to connect to the rear 12v pigtails, which allowed my ot access the frunk and other compartments. Unfortunately I discovered that I had left my 12v lithium jumper on our boat. I was not able to get the vehicle to fully come to life and had it towed to the SC (happily nearby).

This morning Rivian popped the frunk, dropped in a fresh 12v battery and drove it into their garage. Said they had a few more things to check out, but we're pretty sure it is just the 12v battery.

The tech explained that if the 12v battery drops below 10v, the Rivian contactors will not close (= not charge the battery?). Not sure if this something new from a software update. It also appears that the Ohmmu battery has guards to protect it from discharging below a certain voltage. I can see the vehicle interpreting the sudden cutoff as a complete 12v power failure.

Pretty sure the Ohmmu could update their firmware to behave more compatibly with recent Rivian updates, but still kind of a hassle and brittle solution IMHO.

So long as it is not anything else wrong with the truck, I think I will give up on Ohmmu and have Rivian drop in a standard battery. Expensive, but they will stand behind the parts and work.

 

[ksujeff99]

Now fast forward to this morning, after the most recent Halloween update, and the 12V error message is back. I tried a hard reset but no change. The Ohmmu batteries are smart and let me monitor their voltages and current flow through the iPhone app. Everything looks good from this high level view but the truck is upset about something. I’m not sure what to do now. Like you, my truck runs perfectly, but just doesn’t go to sleep so its vampire drain is higher.

I did the 12V reset in the RIDE menu and surprise, surprise IT WORKED! The 12V warning indicator went away immediately and hasn't come back after several drive/sleep cycles.

 

[Rivianero]

I did the 12V reset in the RIDE menu and surprise, surprise IT WORKED! The 12V warning indicator went away immediately and hasn't come back after several drive/sleep cycles.

Based on my experience, I would take that 12v error as a warning. Now is a good time to make sure you have another 12v source handy (i.e., not in the frunk) that you can use to "jump" your Rivy and get going. Beats having it towed.

 

[SwampNut]

Beats having it towed.

Dunno, without the 12v failure and tow, I would have missed all this...

A two hour chat with the driver, a former crackhead, getting his shit together. Someone well outside my demographic, and it's good to be pushed and reminded that your world isn't the center of the known universe.

The hotel closest to the SC was a Mexican hotel. I didn't know there was such a thing. It was interesting, a real flavor, again outside my norm. Interesting place in so many ways.

I decided that evening to go have a couple drinks and a cigar. Found a cigar lounge nearby. Walk in and....I'm the only white person. They looked at me like I'd just pulled a wiggling baby alien out of my pocket. Oh well, I can get along with anyone. I had a GREAT time, met the owner, and helped a 90-some year old regular pick out his first cigar. The owner said "the white dude did what I couldn't talk him into for years." Drinks were excellent, prices low.

Anyway, man, now I wanna kill my battery in the middle of nowhere again, and see what happens. Reminds me of a book called "Random" about a guy who makes 100% of his decisions with a set of dice.

 

[Rivianero]

Hmm... I guess that's also why they call Rivians "adventure vehicles".

Admire your attitude @SwampNut !

 

[zymolysis]

Reminds me of a book called "Random"

Who was the author? Searching for "random" and "book" yields random book generators and suggestions, etc.

 

[SwampNut]

Who was the author?

Penn Jillette. I have to note that I haven't actually read it yet. I skimmed some of the pre-release notes and I have a tangential relationship with the author so we talked about it on a Zoom call and he covered the overview and premise.

https://www.amazon.com/Random-Penn-Jillette/dp/1636140718

 

[variableresults]

I dropped off my vehicle for the same 12v battery message. I got one last year and now within 12 months I got another 12v battery message.

It sounds like Rivian will step up and cover it under 2yr replacement battery warranty even though I am out of the original 3yr / 36k battery mileage warranty by couple thousands miles.

I like the good news from Rivian that they will provide a service option where we clear the error code after the swap. I think down the road I might look at after market options but for now I hope this replacement lasts more than a year or two.

Rivian Developing Service Menu to Let Owners Handle Repairs Like 12V Battery Replacements

Just a point of clarification since there seems to be ongoing confusion about Rivian 12v warranty support—if they were replaced last year, the 3 year original battery warranty being expired is moot. You received an explicit 24 month parts warranty with the invoice for your last replacement. They don’t get to choose to honor that, they’re legally required to by Magnusson Moss.

 

[variableresults]

Based on my experience, I would take that 12v error as a warning. Now is a good time to make sure you have another 12v source handy (i.e., not in the frunk) that you can use to "jump" your Rivy and get going. Beats having it towed.

Nog just the 12v warning—if the truck isn’t going to sleep either, then it’s detecting lower than expected voltage, which is typically a sign of a dying 12v battery. Not sure how that would work with the Ohmmu 12v LFP battery though.

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