Proactive replacement of 12v battery

[joesmith315]

Very helpful! How do you access the RIDE menu?

I have a 22 R1s that has performed well (still getting above EPA even in moderately cold temps) but I do travel in the northeast to hit the mountains so . . . .

Put the car in service mode via settings; click on menu bar 5 times and the RIDE icon will show up when you swipe up; click on the quote 5 times, enter code 33748.

I decided to take a peek and see if there is anything wrong, even though Home Assistant is showing normal operation. I'm not seeing anything out of the ordinary? Also, is that 12V diagnostics option normal?

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[Oldsmobile_Mike]

I was an idiot about this 3 weeks ago. Credit to Tim-in-CA for the following:

This is a great write-up. I'm still trying to wrap my brain around feeding 12V @ 3A back into the battery through the OBDII connector. I'd probably be pretty terrified about doing that on my $70k truck, LOL. But phenomenal outside-the-box thinking! ?

 

[dradam]

I was an idiot about this 3 weeks ago. Credit to Tim-in-CA for the following:

1. OBDII adapter. I got the same brand Battery Tender for this (https://shorturl.at/BCA6e) but you could use any brand. Be careful that some OBDII adapters are only for keeping the car memory when you switch to a new battery and are not compatible with battery charging. This adapter is also 3A (see below).
2. Battery conditioner. I initially bought a 4amp Battery Tender and of course that blew the fuse in the OBD adapter on first use (stupid, I know). Any 3amp Battery conditioner should work fine but I have this one (https://shorturl.at/6kY8w).

I keep both of the above in my frunk, and add my Anker Solix C1000 when going off road out of cell range. If my car bricks and I cannot get into it, I have a T20 and T25 Torx stored in a Hide a Hitch and can access the frunk (see Rivian towing operator instructions here: https://rivian.com/support/article/r1-tow-operator-guide). I can plug the tender directly to the 12V battery and power with the Solix to charge the battery. This may or may not work as the 12V battery needs 30amp sustained to power up. If remote I would likely pull the fireman's loop connector and then disconnect the 12V battery ground connector. That would isolate the 12V and allow me to charge it without the Rivian wanting to draw power. Then after charging for a few hours (this is where I would yell at myself for not having a JNC660 or similar jump box), reconnect the fireman loop and then reconnect the 12V ground.

Complexities:
1. Rear pigtail connectors to the right of the rear hitch. A lot of people (myself included) have thought this could be used to charge a dead 12V battery. Unfortunately, this is NOT a direct 12V battery connection and you cannot use a low amperage battery charger like above. Furthermore, this requires 30A input for up to a few minutes, which will only give you access to the frunk, charging port, and door (different for gen1 vs gen2). Because it's not a direct battery connection unless you have OVERRIDE mode on your charger it won't work. So to use the rear pigtails you've got to have a large amperage battery jump box that has override function. These pigtails are really intended for a direct 12V charging situation (jumper cables to an ICE). It seems to me if I can access the frunk manually utilizing the manual release I would just charge the 12V directly as above. Furthermore, this only connects (AFAIK) to one battery so if the second battery has failed, this will not work (see tow operator guide above).
2. In cabin charging. The OBD port is the best option here as the 12V cigarette lighter ports will not charge the battery if the car is not awake. The OBD port is limited to 3 amps, so if the battery is dead it may take 6 hours or more to charge the 18Ah 12V battery (and that's just a single battery). This likely will not work with a dead battery given the Rivian's desire to boot up the entire system which requires up to 30A sustained.
3. Direct battery charging. You have to take off the cowling under the frunk hood to access the battery(ies). It's also a little of a PITA to get access as the frunk tub interferes with easy access to the batteries. If you have direct access to the battery you'd ideally want high amperage charging and have the advantage of being able to disconnect the high voltage battery (see above). Depending upon how psychotic you want to be about all this a dual function charger/maintainer or separate devices would be an insurance policy to cover more possibilities above. For me, I already have a smaller NOCO GB70 (which I thought would cover my dead battery needs) that I keep in the frunk that I can use to charge a dead 12V battery directly after disconnecting the high voltage battery.

I think all of this is way overkill for normal vehicle uses in civilization. But if you are adventurous with this vehicle away from power/cellular/civilization/easily accessed roads preparing for the worst can be useful.

Disclaimer: I am not an electrician and there are likely hundreds of active users on this forum that know a lot more about this than I. YMMV, etc.

Got home and had a bit of time to digest your post. Thank you showing the products and explaining.

Please comment if I am wrong:

It looks from the online pictures that the tender you use and the obd adaptor have the same plug so no splicing. Just plug to a wall outlet to charger and charger to OBD adaptor to car. I assume the OBD adaptor knows which leads can charge just the 12 V. (I would hate to get that wrong)

In an earlier post Jacopa said : "If the car is left on a level 2 charger the car will pull from shore power ( for 12V) instead of the HV batt ". If that were true the obd tender would not be needed at home plugged in, but people still use these tenders to prevent vampire drain at home. Does shore power charge the 12v directly? Or just the HV which then chargers the 12V. I presume the latter.

I am most concerned (Like you I think) about a 12V failure outside my home. Like you I have a trailer hitch tool box to get into the frunk. I also keep tools in the frunk. It would seem to me that without a 30A continuous source or another ICE it would be hard to reboot this vehicle- especially beacuse the dead 12V battery is not likely able to be recharged.

To me I think it would be easiest to just have a charged drop in replacement battery in the frunk, perhaps maintained every couple of months or before road trips. While the forum has Identified the battery, Rivian won't sell me one. I am not comfortable with the OHMMU BMS and don't want to go there. There arw othe AGM batteries with similar stats, but if the metal posts are in the wrong location they will not drop in. Please share your thoughts.

While I love my R1S and have really had virtually no issues in 8.5K miles I hate having to think about the 12V stranding me. I do check the voltage on the ride menu every few weeks but wish I had a better backup plan.

 

[risingphoenix]

Got home and had a bit of time to digest your post. Thank you showing the products and explaining.

Please comment if I am wrong:

It looks from the online pictures that the tender you use and the obd adaptor have the same plug so no splicing. Just plug to a wall outlet to charger and charger to OBD adaptor to car. I assume the OBD adaptor knows which leads can charge just the 12 V. (I would hate to get that wrong)

In an earlier post Jacopa said : "If the car is left on a level 2 charger the car will pull from shore power ( for 12V) instead of the HV batt ". If that were true the obd tender would not be needed at home plugged in, but people still use these tenders to prevent vampire drain at home. Does shore power charge the 12v directly? Or just the HV which then chargers the 12V. I presume the latter.

I am most concerned (Like you I think) about a 12V failure outside my home. Like you I have a trailer hitch tool box to get into the frunk. I also keep tools in the frunk. It would seem to me that without a 30A continuous source or another ICE it would be hard to reboot this vehicle- especially beacuse the dead 12V battery is not likely able to be recharged.

To me I think it would be easiest to just have a charged drop in replacement battery in the frunk, perhaps maintained every couple of months or before road trips. While the forum has Identified the battery, Rivian won't sell me one. I am not comfortable with the OHMMU BMS and don't want to go there. There arw othe AGM batteries with similar stats, but if the metal posts are in the wrong location they will not drop in. Please share your thoughts.

While I love my R1S and have really had virtually no issues in 8.5K miles I hate having to think about the 12V stranding me. I do check the voltage on the ride menu every few weeks but wish I had a better backup plan.

Okay I am probably not the right person to answer these questions but I'll give my opinion FWIW.

1. Yes no splicing - the OBD adapter connects to the SAE connector of the tender. Plug the tender in, then plug in the OBD and go (it should be on 12V and AGM). Seems pretty bomb proof, at least with the tender.

2. There are a few users that improved/minimized their vampire drain by using the tender on their 12V battery. That would imply that the EXTRA step of conditioning the battery by the tender is NOT being performed by the Rivian's BMS. Bricking occurs when the Rivian goes to sleep but is then unable to wake up due to insufficient 12V power. I assume that by having the Rivian plugged into a power source (I assume Level 1 would probably suffice) the HV battery can boot up from that independent of the 12V battery. I do not think the CCS attached power does anything directly to the 12V battery - I still think all that runs through the BMS on board.

3. Yes I think you are correct about the difficulty in rebooting a bricked Rivian and my 3A tender may not work. Remember, though, that you can disconnect the 12V battery from the Rivian and should be able to charge to enough power to then reconnect. If the 12V battery won't take and hold a charge at all you're screwed whether you have a 30A or not. However, the 30A does gain you access to the vehicle to prepare it for towing (which I think is mentioned in the towing manual).

4. This may be the easiest and most reliable option and, actually, the OHMMU BMS may be the perfect drop in. A lithium battery will be easier to hold a charge and will last longer and should be adequate for temporary emergency usage until you can get back to civilization to replacement with a Rivian approved battery. You'd want to watch their video quite closely and have it available (ie downloaded) to make sure you followed the proper sequence. The OHMMU battery would also be a reasonable power bank battery - would be great to put that in an enclosure to be able to use it to power devices (ie USB and inverter for AC). Or even better, enclose it in a box with a speaker to replace that POS bluetooth speaker in the cabin. Then you've got a spare battery that you can use to charge devices without powering up the tremendous overhead of the Rivian. Sounds like a product for one of the many online 3D printing for EVs companies.

Dewalt makes a combination 30A jump starter and 3amp conditioner that might serve both roles (https://shorturl.at/r0PxQ). If you had a power station to plug it into (I have the Anker Solix or the dream of a OHMMU enclosure mentioned above) you could do either - jump the battery or slow trickle charge and condition.

I don't check the voltage of the battery and I don't stress about it. I just plug the tender into the OBD port every month or so or when road tripping/camping and I think that's pretty good insurance. Remember that the battery tender not only charges the battery but it conditions it to optimize it and will detect automatically if it is unable to take a charge or is failing. So I figure if the tender thinks the battery is okay it's very unlikely to die in the few critical days I'll need it off grid.

 

[dradam]

My responses in red :

Okay I am probably not the right person to answer these questions but I'll give my opinion FWIW.

1. Yes no splicing - the OBD adapter connects to the SAE connector of the tender. Plug the tender in, then plug in the OBD and go (it should be on 12V and AGM). Seems pretty bomb proof, at least with the tender.

Thx Makes sense very good idea.

2. There are a few users that improved/minimized their vampire drain by using the tender on their 12V battery. That would imply that the EXTRA step of conditioning the battery by the tender is NOT being performed by the Rivian's BMS. Bricking occurs when the Rivian goes to sleep but is then unable to wake up due to insufficient 12V power. I assume that by having the Rivian plugged into a power source (I assume Level 1 would probably suffice) the HV battery can boot up from that independent of the 12V battery. I do not think the CCS attached power does anything directly to the 12V battery - I still think all that runs through the BMS on board.

While I would agree that the 12V all runs through the onboard BMS I question that if the 12V died you could boot the car if plugged into level 1 or 2. I believe there have been many instances of people who could not start up even if at home and plugged in to a level 1 or 2 if the 12V has died.

3. Yes I think you are correct about the difficulty in rebooting a bricked Rivian and my 3A tender may not work. Remember, though, that you can disconnect the 12V battery from the Rivian and should be able to charge to enough power to then reconnect. If the 12V battery won't take and hold a charge at all you're screwed whether you have a 30A or not. (not if I have a waiting backup) However, the 30A does gain you access to the vehicle to prepare it for towing (which I think is mentioned in the towing manual).

All the more reason to have a backup 12V in the frunk and maybe a noco- with bypass just to open the doors

4. This may be the easiest and most reliable option and, actually, the OHMMU BMS may be the perfect drop in. A lithium battery will be easier to hold a charge and will last longer and should be adequate for temporary emergency usage until you can get back to civilization to replacement with a Rivian approved battery. You'd want to watch their video quite closely and have it available (ie downloaded) to make sure you followed the proper sequence Yes I have these . The OHMMU battery would also be a reasonable power bank battery - would be great to put that in an enclosure to be able to use it to power devices (ie USB and inverter for AC). Or even better, enclose it in a box with a speaker to replace that POS bluetooth speaker in the cabin. Then you've got a spare battery that you can use to charge devices without powering up the tremendous overhead of the Rivian. Sounds like a product for one of the many online 3D printing for EVs companies.

Yes an OHMMU could be drop in and I like your Ideas about 3D options. I do a lot of 3D printing. (see Printables.com search rivian /dradam.)
I am not sure I would use it long term based on some research I have done. I also have a hard time with the cost, about 4x more I think than a drop in AGM could be.

Dewalt makes a combination 30A jump starter and 3amp conditioner that might serve both roles (https://shorturl.at/r0PxQ). If you had a power station to plug it into (I have the Anker Solix or the dream of a OHMMU enclosure mentioned above) you could do either - jump the battery or slow trickle charge and condition.

Yes, I have though about this exact unit for my garage, but I don't see myself keeping it in the frunk with a backup station-- A simple drop in backup replacement battery would be far smaller and cheaper.

I don't check the voltage of the battery and I don't stress about it. I just plug the tender into the OBD port every month or so or when road tripping/camping and I think that's pretty good insurance. Remember that the battery tender not only charges the battery but it conditions it to optimize it and will detect automatically if it is unable to take a charge or is failing. So I figure if the tender thinks the battery is okay it's very unlikely to die in the few critical days I'll need it off grid.
[/QUOTE]

I certainly may go that route. Sounds better and even easier than tapping my way into the ride Menu !!

Thanks for your prompt and thorough answers. This has been very interesting.

 

[kong]

This seems to be a neat OBD trickle charger solution if you have some spare Dewalt batteries laying around.

https://www.acmetools.com/dewalt-1-...e=1&gbraid=0AAAAADub60tdtSH7yjuPjbqnu9A1hJJRH

 

[citizen]

FYI: The DeWalt DXAEOBD mentioned in this thread is on sale for $12.56 on Amazon. https://www.amazon.com/gp/product/B09Y7M9C82/ref=ox_sc_act_title_1

 

[MacO512]

I see the Dewalt price increased to $30. Interesting idea though.

However I don't think there's enough power in a DeWalt battery for this to be much use. 18v*5AH is 90Wh. My R1 with a single 12v went through I think about 400Wh a day on the tender.

I guess if you were camping or something and just want to keep the vehicle sleeping for half a day to maximize the range maybe this could help.

 

[SSteveEV]

I see the Dewalt price increased to $30. Interesting idea though.

However I don't think there's enough power in a DeWalt battery for this to be much use. 18v*5AH is 90Wh. My R1 with a single 12v went through I think about 400Wh a day on the tender.

I guess if you were camping or something and just want to keep the vehicle sleeping for half a day to maximize the range maybe this could help.

Yeah, I was excited about that DeWalt OBD item too until I did the math and read the reviews of them breaking frequently.

Now that we know the 12v is the cause of the vampire drain I hope we can eliminate something causing that drain on the 12v. For instance if there was a fuse to pull that would disable the 4G connection or something worthwhile for long-term storage.

 

[tekemajik]

Want to clarify my understanding of the issue, sorry for the naive questions. Is the below all correct?

• In the Rivian, the 12V battery powers pretty much everything except for the motors and the heat pump (those are powered with the high-voltage battery).
• The high-voltage battery recharges the 12V battery while driving. It also wakes up periodically to charge the 12V battery while parked (managed by some monitoring system that is powered by the 12V).
• If the 12V battery is old or defective, it may drain so quickly while parked that the system either can't wake up fast enough to charge it, or just decides it's a lost cause and doesn't attempt. If the 12V battery is drained, it can't power the system that starts the high-voltage battery.
• There was some range of vehicles that had 12V batteries that were either defective or prematurely aged due to storage. The replacement will provide a new battery that is expected to be free of these issues.
• Separate from this, it's always possible to drain the 12V battery if there is a vehicle system that is failing to power off while parked or a short somewhere in the wiring.

Thanks in advance.

 

[tekemajik]

Want to clarify my understanding of the issue, sorry for the naive questions. Is the below all correct?

• In the Rivian, the 12V battery powers pretty much everything except for the motors and the heat pump (those are powered with the high-voltage battery).
• The high-voltage battery recharges the 12V battery while driving. It also wakes up periodically to charge the 12V battery while parked (managed by some monitoring system that is powered by the 12V).
• If the 12V battery is old or defective, it may drain so quickly while parked that the system either can't wake up fast enough to charge it, or just decides it's a lost cause and doesn't attempt. If the 12V battery is drained, it can't power the system that starts the high-voltage battery.
• There was some range of vehicles that had 12V batteries that were either defective or prematurely aged due to storage. The replacement will provide a new battery that is expected to be free of these issues.
• Separate from this, it's always possible to drain the 12V battery if there is a vehicle system that is failing to power off while parked or a short somewhere in the wiring.

Thanks in advance.

Updating this to reflect that (according to a Rivian employee on the Reddit forum) the issue on Gen2 is not related to defective or aged batteries. It was a problem of over tightening the bracket that holds the 12V battery in place under the passenger seat, which has led in some cases to damage and leakage. So the batteries are being proactively replaced and brackets tightened properly.

 

[dradam]

Just purchased the Soonish battery terminal adaptors and a FT230d battery so I can have a charged backup 12V in my vehicle if I take long trips. They are for BT19BL-BS batteries to move the posts into the correct location. If I have a 12V failure I would swap the 12V on the road.

It would seem that while the form factor of BT19BL-BS is the same there are slight variations in the post locations. Soonish indicates that there is enough play in the Install that it can be succesfull by rotating the posts.

Can anyone who has swapped their own battery provide exact terminal locations?

TIA

 

[ebellinder2]

After reading the various reports of Rivian owners being stranded when their 12v battery died, I am considering replacing mine proactively. I decided to ask Rivian to confirm if my R1S has one or two lead acid batteries. While support could not answer that question (after initially stating that all Rivians have 2 12v batteries), they suggest I let Rivian perform this service. After finally securing a service appointment, I found out that Rivian will only replace the 12v battery with a similar lead acid battery for about $300. I suspect this would be a foolish replacement. Instead, I'm considering replacing the 12v myself (well, with my handy brother's assistance) with a lithium battery. Am I making the right choice by replacing with a lithium battery in hopes of avoiding a dreaded 12v battery issue? Or are the 12v battery issues related to the build date? Maybe Rivian received a bad batch of lead acid batteries? My build date was in 11/2023 so I'm fairly certain I only have one battery. Am I overthinking this? Thanks!

I have considered the same approach changing battery technology. The risk you take is the algorithm for charging is built on AGM tech. Changing to Li-on and if there were a battery issue could affect your warranty. That’s the only reason I have not changed myself.

 

[kallisti5]

I finally started showing the 12v battery warning after around 60k miles, and 3 years.

Checking the built-in RiDE menu, "Low Voltage Maintenance Status" changes from 1.0 for healthy, to 0.0 for unhealthy.

Side note, there is a 12v reset menu option now in RiDE which is fun.. Ordered the adapters because Rivian using standard 12v 18Ah batteries with a custom proprietary post was stupid.

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