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

[JerseyGreens]

I have two 12V batts, so I charge both.. I wrote up a post with photos of my install here:

https://www.rivianforums.com/forum/...bly-solved-or-hacked.31506/page-9#post-604664

Hey Rob - do you have any OBD2 to SAE adapters? I want to see if you can test the OBD2 method on a dual battery setup.

I just checked my Rivian...and I'm a 3/23 delivery but have the dual battery setup.

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[jplblue]

Hey Rob - do you have any OBD2 to SAE adapters? I want to see if you can test the OBD2 method on a dual battery setup.

I just checked my Rivian...and I'm a 3/23 delivery but have the dual battery setup.

I did that test and it works with dual battery setup:

So I tested the OBDII 12v battery charger adapter (https://www.amazon.com/dp/B007KJ2RZK) over the weekend for about 24 hours. I used this charger (https://www.amazon.com/YHCHKJ-Maintainer-Fully-Automotive-Desulfator-Motorcycles/dp/B0CQRFN7F9/) since it is 3 amps and comes with the SAE connector. I tested both on our 2nd car first before using on the Rivian.

Results:

• It works. Over a little more than 24 hours, the R1S lost 1 mile. This is way better than normal, where we'd lose 1 mile every 5 hours or so. I didn't make any extra effort to keep the car asleep, and would check the app for mileage whenever I felt curious. The 12v voltage sat around 14.2vs at the beginning and end of the test.
• The results are interesting because we have an early R1S with 2 batteries. I'm guessing that the OBDII connects to the "primary" 12v -- and that the "primary" 12v is the one that needs to be topped off to avoid vampire drain? @NY_Rob -- it'd be interesting to see if you get similar results if you only charged the main 12v, which I believe is closer to the driver side.
• I'm guessing that 3 amps is actually not enough to "top off" the 12v battery, given that it seems to run constantly and there were indications that the 12v battery dipped below 14.2v at some points. I don't have any measuring equipment, so this is just my layman observation.
• The charger draws about 57 watts, although I don't think it's constant. I plugged the charger into my Bluetti to test for a few minutes, and it cycled between 57w and 0, but I'm not sure what the total draw over the period is. The charger was constantly warm (not hot).
• It's an easy way to trickle charge the 12v battery without having to get under the hood. Not sure if I'll bother doing it regularly, since it probably annoys the wife. Could be useful in camping/off grid situations, since have have solar to charge our Bluetti/etc.

Please let me know if I'm doing something wrong and that a housefire is imminent.

EDIT: Forgot to mention: if you are using the adapter + charger I linked to, you have to use a reverse polarity adapter: https://www.amazon.com/dp/B0CGKLPFCP . Otherwise, the charger will throw out error due to reverse polarity protection.

 

[NY_Rob]

Hey Rob - do you have any OBD2 to SAE adapters? I want to see if you can test the OBD2 method on a dual battery setup.

I just checked my Rivian...and I'm a 3/23 delivery but have the dual battery setup.

No, sorry... no OBD2 to SAE adapters on hand.

I think the dual to single battery vehicles happened on 3/23 "build date" vehicles. Being a 3/23 delivery vehicle, your build date is probably Jan or Feb 2023?

 

[Yossarian]

Well don't leave us hanging!! Which color solved the problem?? ?

Forest Valley. Drain doubles when you change to Alpine Lake . . .

Edit: insert sarcasm emoji here.

 

[JerseyGreens]

No, sorry... no OBD2 to SAE adapters on hand.

I think the dual to single battery vehicles happened on 3/23 "build date" vehicles. Being a 3/23 delivery vehicle, your build date is probably Jan or Feb 2023?

that's correct. Feb 2023 build. No issues (knock on wood) with the dual battery setup thus far.

 

[HighVoltOverland]

Dumb question is there an easy way to tell if we have one or two 12v batteries? I'm a Mar '23 delivery so right on the edge

Ohmmu, the company that makes the aftermarket lithium battery, made a single and dual battery install video on YouTube.
Could be worth watching both to get multiple upclose angles to reference to help you determine

 

[HighVoltOverland]

@NY_Rob , have you found any need for a battery isolator for your trickle charger?
Or was it just straight to the unused 8mm lugs and everything works?

 

[NY_Rob]

@NY_Rob , have you found any need for a battery isolator for your trickle charger?
Or was it just straight to the unused 8mm lugs and everything works?

Charger lugs right to the posts on the unused fuse terminals on both batts.

 

[HighVoltOverland]

Charger lugs right to the posts on the unused fuse terminals on both batts.

Thanks for the quick response
Have you noticed that one battery is still the primary/ discharges and there therefore needs charging at a higher rate?

For others interested

I pulled the trigger on the Lensun a few days ago
I'll be wiring it straight to the batteries
I have a dual battery charge controller that will go to both batteries simultaneously
Should help with direct sun VD.

Thinking out loud:
May be smarter to build the system around a third battery, to cover the intermittence of solar/ night cycles
Already considering an auxiliary floating battery to run my radio, lights, and fridge full time, maybe it would be smarter to just have that battery set up for a small DC to DC lead to the truck 12v

Oh well, this will be a basic proof of concept for sub niche of those solely interested in the VD issue and 2 battery solutions

 

[SSteveEV]

Forest Valley. Drain doubles when you change to Alpine Lake . . .

Edit: insert sarcasm emoji here.

Don't worry, my wow reaction was also sarcastic

 

[NY_Rob]

Thanks for the quick response
Have you noticed that one battery is still the primary/ discharges and there therefore needs charging at a higher rate?

Once I connected the charger, it took over from there. I have no way to track individual 12V battery charging stats on my NOCO charger.

It would be interesting to track which battery has failed in the dual battery R1 vehicles, but Rivian pretty much always replaces both batts after a failure so there's really no way to know which went.

 

[HighVoltOverland]

Once I connected the charger, it took over from there. I have no way to track individual 12V battery charging stats on my NOCO charger.

It would be interesting to track which battery has failed in the dual battery R1 vehicles, but Rivian pretty much always replaces both batts after a failure so there's pretty much no way to know which went.

I have been toying with installing some shunts to track the 12v but that's another layer of compexity I kinda "ehh" away from

The charge controller gives me the option to "bias" the charging of the batteries, I suppose I'll start with true 50/50 split and go from there

 

[mudito]

Once I connected the charger, it took over from there. I have no way to track individual 12V battery charging stats on my NOCO charger.

It would be interesting to track which battery has failed in the dual battery R1 vehicles, but Rivian pretty much always replaces both batts after a failure so there's pretty much no way to know which went.

Mine is being replaced as I type and I'm pretty sure that the main (driver's side) died or at least it died first.

I was able to jump it from the connectors on the rear of the truck and BRIEFLY got power to unlock and only the driver-side unlocked. it never took power again after that time which makes me think that the battery shorted itself out.

 

[JerseyGreens]

Mine is being replaced as I type and I'm pretty sure that the main (driver's side) died or at least it died first.

I was able to jump it from the connectors on the rear of the truck and BRIEFLY got power to unlock and only the driver-side unlocked. it never took power again after that time which makes me think that the battery shorted itself out.

The fact that these still continue to randomly die give me some serious pause. When was yours delivered/manufactured?

 

[mudito]

The fact that these still continue to randomly die give me some serious pause. When was yours delivered/manufactured?

Mine was probably bound to die. I'm the 2nd owner, the first owner took delivery on December '23. When traded-in then stayed about 4 months within dealers then I purchased it and two months later it suddenly died.

I'm assuming that the extra downtime put an extra toll on it and it didn't hold too long. HAVING said that, I heard from the SC that they see them dying between 2 and 3 years. I just hope they are installing an upgraded unit that might last longer.

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