Confirmed: Newer production R1 only have a single 12v battery, but...

[Megaman0025]

Dual batteries.

Ahh ok thanks.

Sponsored

 

[docwhiz]

If they are the same "engineers" who designed the completely asinine dual 12V battery system that no other manufacturer in the world uses (for good reason), has caused tons of issues, bricked many vehicles at Rivian's expense causing Rivian to abandon their wonderful design just a year into production.. then they should be hanging their heads, not shaking them!

I can't for the life of me figure out why they would have two batteries and two separate power wiring systems. It just seems like this is a recipe for twice as many failures.

 

[C12farmer]

If they are the same "engineers" who designed the completely asinine dual 12V battery system that no other manufacturer in the world uses (for good reason), has caused tons of issues, bricked many vehicles at Rivian's expense causing Rivian to abandon their wonderful design just a year into production.. then they should be hanging their heads, not shaking them!

One day someone will get the real story of why they launched with the dual Pb batteries. I agree it's not a wonderful design, which is why Rivian updated it as soon as they could. Yes, in the automotive world 1 year is fast for a hardware update, unless cars are blowing up or people are dying, none of which is happening here with the 12V issue. Perspective!

I would not be surprised if this updated 12V system what the design engineers wanted all along. There could be multiple reasons they had to launch with what they had. My guess would be supply chain reasons. Maybe the supplier developing this capacitor couldn't be ready in time and had to launch with 2 identical Pb batteries system instead.

Another example of them running out of time is the welded vs cast front subframe. Nobody in Rivian probably wanted to launch with that. They ran out of time developing the single casting and had to lock the design with welded Frankenstein subframe that they only intended for low volume or pre-production.
Anyone know when Rivian switched to the new "front" subframe?

Back to my original comment. Nobody would design a system that put an unbalanced load on part of the battery stack. BMS are expensive and they are not magical. To make them less expensive, they are usually not that good a correcting large unbalances. It is technically possible if you want to make the worlds most expensive BMS.

 

[jpmc86]

I’m not sure if the move to a single battery is indeed to fix issues we’ve seen. To be honest, it could’ve also have been a cost cutting move ie. single magnet, removal of 12v plugs, single horn.

I’m curious what the real move was.

 

[Oldsmobile_Mike]

Ditto January 2023 build. Meridian, 12v frunk and underdash. Two 12v batteries confirmed.

2/2023 build, 19xxx VIN. Cast sub-frame, Meridian audio, two batteries, one magnet, no 12V in frunk or under dash. And no woodgrain whatever-they-ares in the back seats, I don't think. Don't sit back there enough to check, LOL.

And no inserts in the roof rack brackets.

Somebody should make a chart of all these incremental changes we're seeing. Seems like many are cost-cutting (with the exception of the frame). I agree that the battery + capacitor sounds like a better design. Maybe eventually they'll do something about those awful fuse panels?

 

[Beanejar]

@rhuber - thanks for the info. Timely and helpful. Please comment.

I’m a trauma surgeon and getting lights and sirens moved from old car to the S this week. Helps get around to different facilities nicely. Rivian has not been terribly helpful in this endeavor - mostly get ‘not a supported option’ or ‘aftermarket accessories are not approved’ comments. Picked mine up a week after you got yours at the factory, too. Talked with several people then, since and multiple conversations with Service - everyone is keen to not really say much, but hint that it’s OK and won’t likely void a warranty or have significant impact, and immediately disavow any statement.

With your post, I called to see if they could tell me whether or I had two batteries without opening up the front, Service could not. So, opened it up and find my configuration to be like yours - new version.

In my job, I do a lot of er, ‘plumbing,’ but rarely mess with the electrical parts. Don’t know enough in the subject to be dangerous, but can handle installing a light switch. I imagine the very professional installers doing my project have good insight. I wanted to ask for your thoughts, given the knowledgeable pool of people here, and lack of manufacturer support for modifications. I assume that one would connect a 12v aftermarket accessory (Garmin 12v power switch in my case) to the primary battery and not the capacitor? Is that correct? The Garmin has a 0.3mA draw when powered off, so hoping not a huge insult to the battery. When on, lights are all LED and speaker is a low voltage draw as well.

Any other ‘lessons learned’ that might be helpful in this adventure? Lights as shrouds in front window, side rear and rear windows. Have to find a space for the speaker, yet.

Thanks

 

[922110]

@rhuber - thanks for the info. Timely and helpful. Please comment.

I’m a trauma surgeon and getting lights and sirens moved from old car to the S this week. Helps get around to different facilities nicely. Rivian has not been terribly helpful in this endeavor - mostly get ‘not a supported option’ or ‘aftermarket accessories are not approved’ comments. Picked mine up a week after you got yours at the factory, too. Talked with several people then, since and multiple conversations with Service - everyone is keen to not really say much, but hint that it’s OK and won’t likely void a warranty or have significant impact, and immediately disavow any statement.

With your post, I called to see if they could tell me whether or I had two batteries without opening up the front, Service could not. So, opened it up and find my configuration to be like yours - new version.

In my job, I do a lot of er, ‘plumbing,’ but rarely mess with the electrical parts. Don’t know enough in the subject to be dangerous, but can handle installing a light switch. I imagine the very professional installers doing my project have good insight. I wanted to ask for your thoughts, given the knowledgeable pool of people here, and lack of manufacturer support for modifications. I assume that one would connect a 12v aftermarket accessory (Garmin 12v power switch in my case) to the primary battery and not the capacitor? Is that correct? The Garmin has a 0.3mA draw when powered off, so hoping not a huge insult to the battery. When on, lights are all LED and speaker is a low voltage draw as well.

Any other ‘lessons learned’ that might be helpful in this adventure? Lights as shrouds in front window, side rear and rear windows. Have to find a space for the speaker, yet.

Thanks

Yes you would connect it to the primary battery and not the capacitor (capacitors are great for sudden spikes (voltage, watts aka power) but have very low energy density (Ah, Wh aka energy). Just hook up your device for the lights to the primary, if it were me I would make sure there's an in-line fuse from the Positive terminal - I don't know if the Garmin has one built in but it's extremely cheap and simple insurance. You want to do that at the positive terminal as the body is connected to negative terminal and thus if there was a short and you had the fuse at the negative terminal the fuse could be bypassed. Same reason you should always disconnect the negative terminal first. Rivian obviously can't officially say it's OK as it opens them up to liability, your lights, especially if they are LED with low current draw when turned off will be absolutely fine, 0.3mA is nothing. Also from my understanding the vehicle will charge the 12V pretty much whenever it needs it from the main pack.

TLR use the primary battery, throw in a fuse at the positive terminal if your device doesn't include one.

 

[Beanejar]

Thanks for the insight!

 

[922110]

Thanks for the insight!

https://www.amazon.com/Nilight-Stan..._3?keywords=inline+fuse&qid=1687228315&sr=8-3

These are the sorts of fuses I was talking about, they use standard automotive fuses that are dirt cheap. I've seen these used a lot with aftermarket trailer brakes and audio systems.

 

[Joel]

They could replace the 12v battery with a capacitor and eliminate this failure point.

Rivian has done this with the second battery. I can tell you it is still a problem. When the battery fails or is low on charge the whole vehicle has issues. Electrically the vehicle is still split in two. As a result I currently can not do a hard reset because the vehicle does not know it is in park.

 

[docwhiz]

Rivian has done this with the second battery. I can tell you it is still a problem. When the battery fails or is low on charge the whole vehicle has issues. Electrically the vehicle is still split in two. As a result I currently can not do a hard reset because the vehicle does not know it is in park.

Just looks like a bad design. No idea why they would do that.

 

[rhuber]

Rivian has done this with the second battery. I can tell you it is still a problem. When the battery fails or is low on charge the whole vehicle has issues. Electrically the vehicle is still split in two. As a result I currently can not do a hard reset because the vehicle does not know it is in park.

When the voltage dips, some ECUs seem to stay down indefinitely unless you hard reboot by removing 12v power completely. The best way to do this is to open up the frunk, remove the cowl, and remove the negative terminal connector on the battery side.

I've done this multiple times when tinkering and messing up and draining the battery. It should boot right back up. I obv agree this isn't ideal, and they should improve the procedure to recover from low voltage situations.

 

[jpmc86]

This goes to my point. I don’t believe the move to a single battery and a capacitor is meant to fix the problem of ultimately its architecture.

It is most likely a cost reduction effort. Two expensive batteries is more than one expensive battery and inexpensive capacitor. Not to mention, you now have one less item that is probably hard to keep up with in a production setting.

 

[rhuber]

This goes to my point. I don’t believe the move to a single battery and a capacitor is meant to fix the problem of ultimately its architecture.

It is most likely a cost reduction effort. Two expensive batteries is more than one expensive battery and inexpensive capacitor. Not to mention, you now have one less item that is probably hard to keep up with in a production setting.

/shrug

I'll leave the speculation on Rivian's motivation to other folks. Just sharing what I know...

The ECUs that stay powered down are likely doing so on purpose. If you allow them to continuously power cycle as the voltage rises, you're going to just keep seeing them fight for power and reboot each other constantly. This is absolutely solvable, and hopefully they will solve it with software, which is also absolutely doable.

It has never affected me on a vehicle that I haven't messed with. I have no idea how common it is, and whether this matters at scale.

 

[jpmc86]

Great. So just unplug neutral and wait. I feel like this is kind of an old procedure from ICE cars.

Sponsored