An Owner Of A Brick

[Zoidz]

Having experienced this myself, I'm saying that this isn't the way to handle an ordinary maintenance problem. Maybe the batteries need to change. They could have self-diagnostic capability. We can go to the moon, why not be able to tell if a battery is about to go bad. A false alarm is better than battery failure.

We don't know what is causing the failure of the battery. Some failure modes might be detectable by monitoring voltage/current profiles, but others can happen with no advance warning, such as a an internal mechanical failure that creates an open circuit or shorted cell.

We also know that Rivian has contacted some people proactively to replace the battery. But we don't know if that is a result of them monitoring & detecting vs. simply recalling a known bad manufacturing lot .....

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[MaikeruRIV]

Most likely it wont.

Based on the evidence we have as of today, the Car will shut itself down to protect the HV Battery in case there are excessive 12V Charging events/duration (we don't know how much is excessive).

So, upping the voltage would maybe charge the AGM a bit better, but a broken AGM will still be drained as fast. Also, we don't know how much a device like this would impact the DC-to-DC charger as it will alter current during the process. That might just complicate things further.

Gotcha there was also talk in a forum about putting a 1-farad cap in-line with the 12v battery and the charging system to condition the voltage, but without knowing what is causing the breaks, that isn't going to help.

 

[NY_Rob]

What we learned when looking in to Vampire Drain is that increased Vampire Drain in many cases has a direct correlation with a 12V battery that is not healthy/going to fail soon. If we owners know that, Rivian should be able to come up with software that would store the amount of energy used to maintain the 12V battery over the life of the vehicle then have software tell us and Rivian that instead of needing 1.5kWh/day of energy to maintain the 12V battery it's now taking 2.5kWh/day to maintain the 12V battery.

 

[Mark_AZR1T]

The original design intent was reportedly for the second battery to serve solely as a backup, carrying no load-related responsibilities. In the event of a primary battery failure, both you and Rivian would be notified, thereby reducing the likelihood of complete failures.

While it wouldn’t entirely prevent them, it would lower the occurrence enough that it wouldn’t present as a clear pre-existing Rivian issue, as it currently does. It seems they miscalculated the load and/or battery capacity and required the second battery for load carrying as well.

 

[jwanderson88]

I've had my truck back for three or four weeks and everything is normal. I decided I should revisit the situation. I have concerns about the way repairs were done. It was a bad 12-volt battery. I asked someone and they said some Rivians have 2 12-volt batteries and some don't. Does that mean some Rivians have a blank space where the second battery goes? Anyway, the thing I'm concerned about is the need to tow it to a service center. Rivian was billed almost a thousand dollars to tow it to Salt Lake. It seems to work out to $10 a mile. Can a struggling startup afford that kind of "unnecessary" expense. I don't know the relative cost of sending a tech versus towing. Who knows? Maybe it's cheaper to tow it.

A couple of posts back NY_Rob made a comment about the amount of energy used to maintain the 12-volt battery increasing as it ages. That's something that can be measured. There must be a way to detect a failing battery. The result of the problem, dead car, is way out of proportion to the cause of the problem, bad battery.

 

[NY_Rob]

A couple of posts back NY_Rob made a comment about the amount of energy used to maintain the 12-volt battery increasing as it ages. That's something that can be measured. There must be a way to detect a failing battery. The result of the problem, dead car, is way out of proportion to the cause of the problem, bad battery.

If, and there are a lot of "if's" here, you haven't changed any settings, and there has not been a recent update that has affected the whole fleet and if the weather hasn't drastically changed... you see your vampire drain increasing from known historic levels.. it's usually a pretty good indication that one or both of your 12V batts are beginning to go south and have lost some capacity. The vehicle now needs to stay awake more frequently to keep them charged which shows up as increased vampire drain.

The only real method to test the 12V batts would be to disconnect them from the vehicle and test each for capacity on a battery capacity device like the one below. The test would take several hours since the tester is limited to total power dissipation of 85 watts which is around 7 amps at 12 volts. The Rivian 12V batts are 18Ah IIRC, so a "good" one would take 2.5hrs to discharge from a fully topped off state under a 7amp load.

 

[mudito]

I've had my truck back for three or four weeks and everything is normal. I decided I should revisit the situation. I have concerns about the way repairs were done. It was a bad 12-volt battery. I asked someone and they said some Rivians have 2 12-volt batteries and some don't. Does that mean some Rivians have a blank space where the second battery goes? Anyway, the thing I'm concerned about is the need to tow it to a service center. Rivian was billed almost a thousand dollars to tow it to Salt Lake. It seems to work out to $10 a mile. Can a struggling startup afford that kind of "unnecessary" expense. I don't know the relative cost of sending a tech versus towing. Who knows? Maybe it's cheaper to tow it.

A couple of posts back NY_Rob made a comment about the amount of energy used to maintain the 12-volt battery increasing as it ages. That's something that can be measured. There must be a way to detect a failing battery. The result of the problem, dead car, is way out of proportion to the cause of the problem, bad battery.

All great questions that we are asking ourselves as well. The good thing is that Rivian is doing a lot of Proactive Batteries replacement, so there's that.

 

[jwanderson88]

Another idea shot down. Maybe it isn't possible to detect a bad battery. Having a bricked car is the worst thing that can happen and you'd think solving this problem would be a higher priority. Evidently it isn't a high priority unless it happens to you.

 

[mudito]

Another idea shot down. Maybe it isn't possible to detect a bad battery. Having a bricked car is the worst thing that can happen and you'd think solving this problem would be a higher priority. Evidently it isn't a high priority unless it happens to you.

As a victim of the same issue, I agree. It's one of the worst things it can happen... Hence why I started to be very anal with monitoring my VD Drain and sleeps cycles.

Now, with new batteries, I know how my truck behaves and if that changes, I can anticipate myself to a failure.

I would like to believe that Rivian is doing the same and monitoring certain parameters more closely to give earlier notifications to owners when a 12V might be dying. Also, they can improve/alter the behavior on when the 12v charging circuitry "gives up" and shuts itself (and the entire car) down.

If that's better managed, we might get more lead-time to a failure and avoid bricking, hence avoiding Towing costs (under warranty).

Also, there are multiple changes on new units on battery location so I'm assuming that lots have changed on Gen2 vehicles. We'll see in a couple of years how that worked out

 

[godfodder0901]

I've had my truck back for three or four weeks and everything is normal. I decided I should revisit the situation. I have concerns about the way repairs were done. It was a bad 12-volt battery. I asked someone and they said some Rivians have 2 12-volt batteries and some don't. Does that mean some Rivians have a blank space where the second battery goes? Anyway, the thing I'm concerned about is the need to tow it to a service center. Rivian was billed almost a thousand dollars to tow it to Salt Lake. It seems to work out to $10 a mile. Can a struggling startup afford that kind of "unnecessary" expense. I don't know the relative cost of sending a tech versus towing. Who knows? Maybe it's cheaper to tow it.

A couple of posts back NY_Rob made a comment about the amount of energy used to maintain the 12-volt battery increasing as it ages. That's something that can be measured. There must be a way to detect a failing battery. The result of the problem, dead car, is way out of proportion to the cause of the problem, bad battery.

The vehicles with one 12v have a capacitor in place of the secondary 12v. With the covers on, it looks very similar.

As far as testing 12v and predicating failure, this is an interesting read:
https://vtechworks.lib.vt.edu/

 

[KBabione]

Having a bricked car is the worst thing that can happen...

I'm going to add do your statement: Having a bricked car is the worst thing that can happen and not knowing when it might happen to you compounds that.

It, knock on wood, hasn't happened to us, but I feel there's a "hierarchy of badness" of sorts related to it:

• Happens at home when you have other vehicles you can use while it's resolved - bad, but probably least bad
• Happens at a location near home while you're out and about - More inconvenient, but hopefully manageable
• Happens while you traveling far from home - This is the one that scares me the most...Waking up at a beautiful VRBO in the middle of nowhere and your Rivian is simply dead

Clearly, there are are almost infinite themes and variations of the above bullets. I'm happy to see Rivian proactively reaching out to customers to get their batteries replaced before brickdom and hope whatever algorithm they use will continued to be refined and we'll see fewer and fewer posts like the OP's.

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