What I learned from my 12V battery swap

[Kuro-Rivian]

I believe the Rivian batteries are AGM. SLA batteries can be AGM or lead plate. They have the same basic chemistry. Both the comparable batteries the OP compared the Rivian battery to, are AGM batteries by Chrome Battery. Unfortunately, you still can't discharge real low with an AGM as they will not recover ether. I have gone through many AGMs in my Jeeps, trucks and bikes. They are better at handling vibrations and are able to mount in any direction.

All of this is true. And these days most decent battery chargers can desulfate batteries to bring them back to ALMOST new. It's takes while though so it's not practical when faced with dead battery.

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[Stack]

Can't the error codes be cleared with an OBD2?

 

[Brewbud]

All of this is true. And these days most decent battery chargers can desulfate batteries to bring them back to ALMOST new. It's takes while though so it's not practical when faced with dead battery.

Yes, I have a nice battery charger with a desulfate setting. Out of 4 batteries, it has sort of brought back one that lasted for at least a year. All of them took forever though. I am glad I didn't trust any of them.

 

[pc500]

The two batteries was almost certainly a packaging and commodity concern. They are cheap and making a custom battery part would be annoying.

 

[zigzagzap]

I'm far from an expert, I know enough to be dangerous (this is SO true!) but I'd be cautious about doing that. We don't know if the Rivian BMS for the 12v has the capability to charge a lithium battery correctly.

I reach out to the folks at Ohmmu.com to distill down the facts and provide accurate information usefully to all forum members. I feel very comfortable with their reply and will upgrade my battery once I have delivered and completed my due diligence.

"There is no issue whatsoever with the Rivian charging our batteries. This isn't something we just throw out there, thorough testing has been done and operating voltage of the Rivian 12V is not a problem for our battery. We actually bought a Rivian R1T at beginning of 2022 and spent most of that year in development."

https://www.ohmmu.com/rivian

 

[Dark-Fx]

I reach our to the folks at Ohmmu.com to distill the facts and provide accurate information usefully to all forum members. I feel very comfortable with their reply and will upgrade my battery once I have delivery and completed my due diligence.

"There is no issue whatsoever with the Rivian charging our batteries. This isn't something we just throw out there, thorough testing has been done and operating voltage of the Rivian 12V is not a problem for our battery. We actually bought a Rivian R1T at beginning of 2022 and spent most of that year in development."

https://www.ohmmu.com/rivian

I still think having lithium for a 12V system is a mistake for any vehicle that regularly spends time in significantly below freezing temperatures. Charging in those temperatures is always going to be a problem unless they are using an exotic electrolyte.

 

[zigzagzap]

I still think having lithium for a 12V system is a mistake for any vehicle that regularly spends time in significantly below freezing temperatures. Charging in those temperatures is always going to be a problem unless they are using an exotic electrolyte.

Noted. Fortunately, we rarely get below freezing in Tidewater, VA

 

[Kuro-Rivian]

I reach out to the folks at Ohmmu.com to distill down the facts and provide accurate information usefully to all forum members. I feel very comfortable with their reply and will upgrade my battery once I have delivered and completed my due diligence.

"There is no issue whatsoever with the Rivian charging our batteries. This isn't something we just throw out there, thorough testing has been done and operating voltage of the Rivian 12V is not a problem for our battery. We actually bought a Rivian R1T at beginning of 2022 and spent most of that year in development."

https://www.ohmmu.com/rivian

Thanks. I'm a huge right to repair advocate and not afraid of tearing into ANY vehicle. I have the skill and means to do it. I've never been afraid of adding aftermarket items to even the newest fresh off the lot car. In this case I'd be a little leery about swapping out the 12V battery considering the electronic complexity of the truck. Chances are it'll be fine (though cold IS an issue for most of us) but you're potentially setting yourself up for a warranty issue. AND the real issue that I have is adding a lithium battery has no demonstrable benefit. You're adding something that does nothing to improve the performance of the vehicle. The 12V issue seems to a bit of a fluke and likely not repeatable. I doubt we hear of it much this point forward.

 

[Kuro-Rivian]

Also it appears that Rivian may be polling/pulling data on trucks, contacting owners and proactively replacing 12V batteries what had excess 12V battery drain but didn't meet the "brick the truck" threshold.

 

[White Shadow]

Normally I would agree with you. But because of the the electronics involved I think we've moved beyond battery replacement being a simple DIY exercise even for ICE vehicles.

I used to rail against BMW because you have to reset the ecu to recognize a new battery. They were one of the first, but their BMS did create 5-7 year battery lives as a result. Now that system looks so quaint!

For vehicles like that (including my Audi), there's a simply battery registration process that can easily be done for the DIY crowd. And even if you don't do it, the car will be just fine. It's really just about the charging strategy for a newly installed battery.

 

[Kuro-Rivian]

Yes I know, it simply resets the clock on the clock on the bms. The main (or even sole) is to extend & maximze battery life as I mentioned.

 

[Kalorado]

Also it appears that Rivian may be polling/pulling data on trucks, contacting owners and proactively replacing 12V batteries what had excess 12V battery drain but didn't meet the "brick the truck" threshold.

Apparently I'm on that list. They reached out to me this weekend and have a mobile scheduled for this Friday to R/R 12v batteries despite never having a problem with the 12V. My truck is a 46** VIN with 21,000 mi.

 

[maddave12]

My 12v batteries went wonky over the weekend. I already had a service visit scheduled (to bring me a spare, which then showed up with part of the jack missing), and Rivian had added a "courtesy inspection" of the 12v system to my work order before any issues showed up. Oddly, the tech didn't seem to know that when he arrived, and I was "lucky" he had batteries with him for appointments later in the day.

The tech was friendly and let me ask a few questions while I watched him work (which he must've just loved, but I wanted to learn stuff). Things I learned:

1) I do NOT have a conveniently dangling set of wires where a 12v outlet would have been in the frunk (VIN 159xx).
2) Order matters when connecting up the new batteries. He went through quite a sequence of "connect these, calibrate those, connect something else...", and
3) he needed the laptop to reset some codes and recalibrate a bunch of moving stuff (windows, seats, steering wheel, etc.) before it was back to normal.

I'm glad I wasn't "just" replacing a battery by myself.

Update:

It turns out the tailgate and gear tunnel doors were inoperative after this procedure. My tech came back out on a Saturday (on his own time, I suspect), and first concluded there was a problem with the controller for those circuits, and I'd need to put in a ticket for a major procedure involving pulling panels off the bed, etc.

That sounded really, really unlikely to me, given it started as a result of the work he had done 5 days earlier. Yes, a surge could've killed something while he was connecting/disconnecting, but I'm an engineer, and I'm strongly biased toward simple explanations, and I nudged him into rechecking his hookups before he left. They were apparently fine, BUT, disconnecting and reconnecting everything from the 12v batteries brought it back to life.

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