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

[Oldsmobile_Mike]

The irony of the top two threads on the forum being "12V Battery Replacement Bricked My R1T" and "Confirmed: Newer production R1 only have a single battery, but..."

People are going to have to be more careful than ever with these systems, imho. Especially since all the instructions currently assume two 12V batteries.

Waiting to see what happens when someone tries the Ohmmu upgrade and slaps a second 12V battery in there in place of the capacitor. #shrug ??

Sponsored

 

[NY_Rob]

I'll be even happier the day they decide to scrap the 12V batts completely and just run a 14V buck converter off the traction battery for the 12V legacy devices. It's not like the 135kWh 450V battery pack would ever run low enough to be unable to supply a few amps at 12 volts.

 

[miasm]

This is pretty interesting to me. Seems like they sized two batteries to handle the spike / load, and then realized that that becomes problematic and they could get by with the capacitor, which is a great solution, honestly.

The intriguing part for me is that the capacitor is the same size / form factor as the other 12V battery, so it might have a pretty good amount of capacity; maybe half or more of the actual 12V? This could potentially help phantom drain too, since you can charge the capacitor much, much, much more quickly than a lead-acid, and having the HV on is one of the bigger phantom drain draws, I *think*. Right now they turn on the high voltage system, and slowly charge the batteries and then turn it off. It takes a decent amount of time. With the capacitor, they might be able to fire up the HV, charge the capacitor super quick, and then turn the HV off, saving a decent amount of battery....this is my naive hope.

 

[C12farmer]

Is this change reflected in their user manual? It's shocking how a company can make a user accessible hardware change and not properly document it to the user.

They probably protect themselves by saying 12V batteries (now capacitors also) should only be serviced by Rivian.

 

[Friscorays]

I hope this is not a stupid question. I keep most of my ICE vehicles on battery tenders. Any reason this would not be a good idea on a Rivian?

 

[markp]

I hope this is not a stupid question. I keep most of my ICE vehicles on battery tenders. Any reason this would not be a good idea on a Rivian?

Well the user manual says to keep the vehicle plugged in when not in use, so that's kind of like a 240V battery tender.

 

[C12farmer]

Rivian service was very helpful over the phone and I actually got a call back from a tech in the local service center. They asked me some questions and then asked if I had been trying to charge the left side and had removed the red lead. I had. The tech then informed me that the left side, which is the same form factor as a battery, is actually a capacitor in the new builds.

When you say it would not take a charge, what do you mean? What was the voltage of this capacitor when you first got to it? Was it fully discharged or already charged to 12V?

 

[electruck]

I hope this is not a stupid question. I keep most of my ICE vehicles on battery tenders. Any reason this would not be a good idea on a Rivian?

You don't need to, and most likely should not, connect a battery tender to the Rivian 12V. The high voltage battery pack is already taking care of that for you - it is always topping off the 12V as needed. The HV pack will eventually drain if it sits long enough hence the recommendation to keep the vehicle plugged in when not in use (especially if the vehicle will be parked for several weeks).

 

[Dark-Fx]

I hope this is not a stupid question. I keep most of my ICE vehicles on battery tenders. Any reason this would not be a good idea on a Rivian?

12V battery maintenance is just part of what the EV does with energy from the high voltage pack. You should never have to do that.

 

[rhuber]

When you say it would not take a charge, what do you mean? What was the voltage of this capacitor when you first got to it? Was it fully discharged or already charged to 12V?

It showed no voltage whatsoever with a multimeter. My best guess is that this is some kind of protection against me killing myself. The positive (left side) terminal of the capacitor measured to the battery ground did show a voltage but that appears to be a direct connection of the positive, because even when I disconnected the positive terminal of the capacitor from the vehicle, I saw voltage across the line, which had to be coming from the actual battery side.

As many have mentioned, actual wiring diagrams would be great

 

[opnwide]

Yep, I should have mentioned. So in this video from Ohmmu about replacing the batts, you can see there is a black negative terminal on the left side of the left battery (when facing them from the front). The capacitor has red insulation instead of black in this location.

So OP I made a quick video, am I correct about this black terminal=battery and not capacitor?…

 

[rhuber]

So OP I made a quick video, am I correct about this black terminal=battery and not capacitor?…

Yep. Correct. Since so many are asking I’m just going to go make a similar video brb.

 

[rhuber]

So OP I made a quick video, am I correct about this black terminal=battery and not capacitor?…

Here is the capacitor version. Yes, I misspoke when I said “two batteries” in the video I just made in 45 seconds.

 

[HighVoltOverland]

Here is the capacitor version. Yes, I misspoke when I said “two batteries” in the video I just made in 45 seconds.

Idk why there were so many die hard skeptics between the two threads from today

“Pics or it didn’t happen” because obviously you were just a dagum liar and trying to trick us!

 

[pricedm]

Well the user manual says to keep the vehicle plugged in when not in use, so that's kind of like a 240V battery tender.

For what its worth, my 4.5 year old Tesla is on the original 12v accessory battery. Car is plugged in (and garaged) when not driving. I think keeping these 12v legacy batteries on a power source is very helpful in preventing "dead car" issues. I can't wait for the 12v lead acid battery to be replaced with a lithium solution.

Sponsored