Gen 1 Vampire Drain (Possibly) Solved (or Hacked)

[jplblue]

By my math fwiw, it's basically 400w of power when all the computers are humming (~1 MPH drain, or 6.5%/day (R1T PDM Max), you can force this by turning on the power outlets)

OTOH, a normal quiet day is more like 1%, which translates to ~60w of draw. It's not really continuous of course as things cycle to, we presume, charge up the 12v system, and whatever other routine maintenance tasks there may be.

Will that Ohmmu battery, which has ~3x the capacity, allow the 12v charger to cycle less often, allowing that 60w average to be driven down lower? I had a chat with their support folks, they said maybe but are doubtful it will be measurable, but what the heck I ordered one and will find out.

Also I've got the parts I think for the battery tender idea, very much TBD there too, I'm doubting the trailer hitch power is active 24/7 but maybe I'm wrong...if it isn't I'll need to dig into the front, but I need to do that soon anyway to upgrade the horn

With either of the above options, the altered sleep cycle should show up clear as day in Electrafi, so ?

Would love to hear your experience with the Ohmmu battery once you get it. Do you think it makes a difference if you have 2 12v batteries vs 1?

Why do you think that the trailer hitch power is not active 24/7? Have you seen the video where a dead R1S was "jumped" using the trailer plug?

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[dduffey]

Let me throw out another consideration. I do not have the ability to charge at home and just had to replace the 12v batteries on my LE R1T. I was quoted $822 for the replacement. ...

$822!?!? Oh my, can others confirm/share their experiences? I have an R1T with two low voltage batteries. Will Rivian "upgrade" old R1Ts to a single battery?

I am likely approaching the age where a 12v battery will need to be replaced. Would love to be proactive and try to future proof.

I've had 3 12v battery failures on our Teslas. Two were covered under warranty. Third was basically a normal cost (don't recall exactly, but not approaching $1k for sure) and that was mobile service (no additional cost).

 

[CarlM408]

Okie dokie, well here we go...power draw started at 3w and then over a few minutes came down to 2w and is sitting there now while the software update installs
Proximity locking & gear guard disabled (and at home anyway, doors unlocked), [email protected]%, and can leave it just sitting there unplugged from our L2 charger for the next 24h or so.

Food for thought, in Camp Mode, there was no power from the trailer plug. Tried that first and then had to wake it up to light up the port.

 

[CBRacerX]

Okie dokie, well here we go...power draw started at 3w and then over a few minutes came down to 2w and is sitting there now while the software update installs
Proximity locking & gear guard disabled (and at home anyway, doors unlocked), [email protected]%, and can leave it just sitting there unplugged from our L2 charger for the next 24h or so.

Food for thought, in Camp Mode, there was no power from the trailer plug. Tried that first and then had to wake it up to light up the port.

Good info on Camp Mode. Looking forward to the results!

 

[Zoidz]

...
I have an R1T with two low voltage batteries. Will Rivian "upgrade" old R1Ts to a single battery?
...

No one that I know of has reported such an upgrade, and IMO it's questionable if they will offer it. From various reports in the past, the 2 battery vehicles have a "split in two" wiring harness. Each battery powers a different portion of the vehicle, they are not in parallel with both batteries powering the entire vehicle. The single battery vehicles have a parallel capacitor for surge power but the entire vehicle is powered from that single source.

I'm not saying it's impossible to do, just seems unlikely that Rivian will offer it.

 

[Bobrobheimer]

If this proves to be an effective measure I would look at adding a single solar panel to the top of my future gfc camper and a small solar charge control to allow 12v top up whenever there’s sun. Thoughts on this idea?

 

[usulio]

The solar panel ideas are cool, but a lot of drain happens at night....I generally like the disconnect switch idea...

 

[usulio]

To summarize, the vehicle is using some amount of power X from the 12V battery while it's just sitting there (possibly waking up some systems, transferring data, whatever), and it's also losing some amount of power Y from inefficiency in recharging the 12V battery from the high-voltage battery. Did I get that right?

If so, then the 12V disconnect switch would save both X and Y. Whether the solar panel works depends on if it provides enough power to do X; if so, it would prevent Y as well. An external battery pack could keep the 12V charged, powering X and preventing Y. Anyway, it would be cool to try to get data on what X and Y are.

 

[usulio]

By my math fwiw, it's basically 400w of power when all the computers are humming (~1 MPH drain, or 6.5%/day (R1T PDM Max), you can force this by turning on the power outlets)

OTOH, a normal quiet day is more like 1%, which translates to ~60w of draw. It's not really continuous of course as things cycle to, we presume, charge up the 12v system, and whatever other routine maintenance tasks there may be.

Will that Ohmmu battery, which has ~3x the capacity, allow the 12v charger to cycle less often, allowing that 60w average to be driven down lower? I had a chat with their support folks, they said maybe but are doubtful it will be measurable, but what the heck I ordered one and will find out.

Also I've got the parts I think for the battery tender idea, very much TBD there too, I'm doubting the trailer hitch power is active 24/7 but maybe I'm wrong...if it isn't I'll need to dig into the front, but I need to do that soon anyway to upgrade the horn

With either of the above options, the altered sleep cycle should show up clear as day in Electrafi, so ?

This is kind of what I'm trying to understand with X and Y above. If the 400W computers set to wake up and run every few hours, then recharging the 12V isn't actually the problem. Rivian would just be using a lot of juice on idle (X). But maybe it's the act of recharging the 12V that causes the computers to wake up or something (Y). Will be great to get data!

 

[Zoidz]

To summarize, the vehicle is using some amount of power X from the 12V battery while it's just sitting there (possibly waking up some systems, transferring data, whatever), and it's also losing some amount of power Y from inefficiency in recharging the 12V battery from the high-voltage battery. Did I get that right?

Pretty much correct.

If so, then the 12V disconnect switch would save both X and Y. Whether the solar panel works depends on if it provides enough power to do X; if so, it would prevent Y as well. An external battery pack could keep the 12V charged, powering X and preventing Y. Anyway, it would be cool to try to get data on what X and Y are.

A disconnect switch would address the drain problem, but potentially introduce other issues.
This Thread discusses some experiences owners had with 12 volt battery failure/replacement. From the vehicle's perspective, every time you would turn off a battery disconnect, it's a total power failure which has been reported to cause other issues, anywhere from nuisance codes to bricking. It seems this might be more problematic on the dual battery vehicles than the battery/capacitor vehicles. The capacitor, in part, is there to provide additional power for surges or when the battery is removed. But the capacitor is going to drain in minutes, not hours.

Personally, with the reported secondary issues related to 12 volt battery failure, I'd rather manage the 12 volt battery failure when I am warned about it or it just happens, as opposed to increasing the likelihood of other problems caused by frequent use of a disconnect. Based on these reports, installing and using a disconnect would likely INCREASE the probability of a problem. Why do that to yourself, especially over a few pennies of electricity?

 

[d15b7]

I’m actively watching this thread, as my ‘22 R1T (original 12v batteries in it still) has significant overnight losses (anywhere from 2kwhr to 5kwhr with no rhyme or reason. I have gear guard turned off at my house and proximity lock/unlock turned off at my place too). This situation is not causing me a real issue, it just annoys me that it is so wasteful. Now, onto what I can add here to the discussion: I own 7 ‘special’ cars (cars that are vintage or special days only or track cars) and I keep all of them on battery tender/maintainers 24/7 (this makes sure they will start after long months sitting and also greatly extends the 12v battery life. Like I get 8-10 yrs out of the batteries typically). The tenders/maintainers use very little current (I honestly don’t notice an elevation of my electrical bill when I put them into use). I’d guess that running a tender on the 12v battery overnight would use 1/10th or less the kwhr that my R1T is wasting by waking itself up and using its high voltage battery to charge the 12v batteries (I think the big waste here is that the entire truck is powering up just to use a small fraction of its energy to go into the 12v, but a lot of the other systems have to start up in order to do this).

the major reason I’m not putting a tender on the 12v of my R1T is because I use it every day and I’m positive I’d occasionally forget to unhook the tender and I’d drive away with it still plugged in and destroy the tender/rip out the 12v hookup from the rear of the truck and I certainly don’t want to do that. If I could figure a way to fabricate a soft pull breakaway (maybe a magnetic keyed plug?) then I’d go that route.

 

[CarlM408]

...the major reason I’m not putting a tender on the 12v of my R1T is because I use it every day and I’m positive I’d occasionally forget to unhook the tender and I’d drive away with it still plugged in and destroy the tender/rip out the 12v hookup from the rear of the truck and I certainly don’t want to do that. If I could figure a way to fabricate a soft pull breakaway (maybe a magnetic keyed plug?) then I’d go that route.

lol, 12v tender mag-safe! That's a product in need of invention.

Test Update: Starting at 10PM last night, the truck slept for just over 4 hours, woke up for 90 minutes burning .230kwh, probably thinking about existential issues and rolling over again and again...and then went back to sleep for 3.5 hours and counting.

 

[usulio]

A disconnect switch would address the drain problem, but potentially introduce other issues.
This Thread discusses some experiences owners had with 12 volt battery failure/replacement. From the vehicle's perspective, every time you would turn off a battery disconnect, it's a total power failure which has been reported to cause other issues, anywhere from nuisance codes to bricking. It seems this might be more problematic on the dual battery vehicles than the battery/capacitor vehicles. The capacitor, in part, is there to provide additional power for surges or when the battery is removed. But the capacitor is going to drain in minutes, not hours.

Personally, with the reported secondary issues related to 12 volt battery failure, I'd rather manage the 12 volt battery failure when I am warned about it or it just happens, as opposed to increasing the likelihood of other problems caused by frequent use of a disconnect. Based on these reports, installing and using a disconnect would likely INCREASE the probability of a problem. Why do that to yourself, especially over a few pennies of electricity?

Yep, it seems very risky. For me, the benefit would be less so at home, and more in a camping or travel situation where the power is really needed for range.

 

[usulio]

lol, 12v tender mag-safe! That's a product in need of invention.

Test Update: Starting at 10PM last night, the truck slept for just over 4 hours, woke up for 90 minutes burning 230kwh, probably thinking about existential issues and rolling over again and again...and then went back to sleep for 3.5 hours and counting.

Interesting! That's not too much power loss for a Rivian. Do you have any monitoring to see how much data it uploaded/downloaded during those 90 minutes (I believe that's what it's doing)?

 

[mkhuffman]

I think the big waste here is that the entire truck is powering up just to use a small fraction of its energy to go into the 12v, but a lot of the other systems have to start up in order to do this.

This is exactly the issue, IMO. The HVB BMS has a ton of overhead, including running cooling/warming systems to keep the HVB operating safely. You can't just tap into the HVB and pull a little power off. You have to turn on all those systems while it is being used. It is perfectly fine for transportation, but to charge a tiny 12V battery? Extremely wasteful.

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