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

[shrink]

Not back with my car yet (I’m in HNL for a layover), but check the car status and woke it up since it’s been 21 days/3 weeks. :

8/9/2024 to 8/30/2024:

SOC 69% to 68%

0% loss over 2 weeks
1% loss over 3 weeks

*I did accidentally charge the car a few days ago for 3 minutes @ 240V and 40 amps. SOC stayed at 68% and car added 1 mile of range per the app.

Will provide additional photos and details after I get home.

Sponsored

 

[NY_Rob]

One question for the successful experimenters ... how much external power was used to power the 12V battery?

My trickle charger consumed 0.52kWh over 48hrs, so 0.26kWh/day keeping the 12V batts charged.

Over a month's time, at that rate it will cost me $1.95 to keep the 12V batts charged.

 

[NY_Rob]

I have to end my test at 96hrs because I need to use the truck tonight, results below:

Start range: 143mi
End range 141mi
Test duration 96hrs

Cost to run trickle charger for 4 days: $0.26
Cost to recharge 2 mi lost range over 4 day test (1kWh): $0.25
Total cost over 4 day test: $0.51


Without the trickle charger, over the same 4 day period I would have lost 1.7kWh/day for a total of 6.8kWh which would have cost me $1.70 to replenish.

If you run the numbers out to a month and a year, that's when you see big savings using the trickle charger.

 

[Charged]

I guess I could maybe see 12% in the winter, with the truck having to heat the battery. I certainly wouldn’t want to leave it unplugged for long in freezing conditions. And I doubt our battery tender solution would be sufficient to do much about that, anyway.

As others have noted, 12% far exceeds the losses that owners have reported. My R1T is always outside, and mostly parked unplugged. I drive infrequently, often leaving the truck parked for 4-5 days. Daily loss this summer has been ~ 1.25%. When temperatures remain well below 0˚F for extended periods (which happens here in mid-winter) charge drops as much as 2.5% daily, but more typically the loss has been just under 2% daily throughout the winter. I do own a Level 2 charger, but never actually had it installed (electricians in my rural area were not interested in the installation job). I quickly learned that Level 1 charging is quite adequate for my infrequent driving, and is perfectly fine for charging even in the coldest NH weather. So I stopped searching for an electrician. Last winter I did sometimes pre-condition the truck while connected to the charger, in order to extend my range for the longest trips. That worked well.

Seeing the impressive results shared in this thread I do plan to use a battery tender now, primarily because I believe it should help to protect the 12V system.

 

[josh0]

As others have noted, 12% far exceeds the losses that owners have reported. My R1T is always outside, and mostly parked unplugged. I drive infrequently, often leaving the truck parked for 4-5 days. Daily loss this summer has been ~ 1.25%. When temperatures remain well below 0˚F for extended periods (which happens here in mid-winter) charge drops as much as 2.5% daily, but more typically the loss has been just under 2% daily throughout the winter. I do own a Level 2 charger, but never actually had it installed (electricians in my rural area were not interested in the installation job). I quickly learned that Level 1 charging is quite adequate for my infrequent driving, and is perfectly fine for charging even in the coldest NH weather. So I stopped searching for an electrician. Last winter I did sometimes pre-condition the truck while connected to the charger, in order to extend my range for the longest trips. That worked well.

Seeing the impressive results shared in this thread I do plan to use a battery tender now, primarily because I believe it should help to protect the 12V system.

I’ve never left mine unplugged for any significant time while it was that cold out, so haven’t had first-hand experience with the impact of battery warming, though it did seem to noticeably slow charging back when I was stuck on a 15A outlet.

I’m definitely planning on experimenting with a solar tender to combat VD. Hopefully ending the day with the 12V topped up will be enough to avoid the need to charge overnight (but should still at least lessen it). I still spend enough time in places without access to overnight charging that it would be really nice to minimize my need to drive somewhere just for a charge.

 

[josh0]

Somebody really needs to start marketing a product specifically for this using old WWII Veneral Disease posters.

 

[shrink]

Experiment officially done. Battery charger disconnected and car is ready to be driven!

Final Results:

8/9/2024 to 8/30/2024

3 weeks/21 days (and 510 hours to be most precise):

1% loss total
0% loss in the past 2 weeks

*latest software update downloaded over LTE during this period. I think it caused the 1% loss
** I accidentally charged the car for 3 minutes a few days ago at 240 V and 40 amps. App said 1 mile of range was added but SOC stayed at 68%

Gen 1 2023 R1S, Large, Quad

Shipping Mode
Proximity Off
WiFi Off
Bluetooth Off
Gear Guard Off at Home
Data and Privacy - all off except for location
AC off
Software: 2024.19.04 (Not the latest with Connect+)

Photos below. I didn’t close the frunk all the way because I wasn’t sure it would close with the battery leads attached. I made sure it would not latch by putting a grocery bag over the latch in case something went wrong and I needed to access things.

I’ll check the usage of the battery charger when I head back to the mainland.

This was wildly successful for me. Hope others can benefit. I’m most curious about how much electricity the battery charger is using and if the latest software update will make any difference.

 

[NY_Rob]

Awesome @shrink !!

I think your battery charger draw will be similar to mine, somewhere in the area of 0.26kWh/day.

It's amazing that just by keeping the 12V batts charged you can reduce vampire drain to almost zero even over a long period of 21 days.

For people going on trips and having to leave their vehicles unattended for long periods this would be the solution to coming back to a bricked vehicle.

 

[chops]

One question for the successful experimenters ... how much external power was used to power the 12V battery?

i got a new schumacher 12V/5A charger and at idle it uses about 15-25W to maintain the battery which adds up to about 0.5kWh every 24hrs.

pics of my install:

 

[CarlM408]

Got a couple experiments running today...gotta love a good 3 day weekend!

2A load on a fully charged Ohmmu, with GoPro watching the voltage and time. Will be comparing this with the Rivian's AGM battery after swapping to get a feel of the actual capacity difference between the two. The Ohmmu folks are a bit cagy about 'capacity' and prefer to speak "Reserve Capacity", which does make some sense but makes it hard to compare. All we care about is can we delay voltage dropping to the point that the HV>12v recharger kicks on.

Also! Camp battery running through battery tender plugged into the OBD port. This is quite possibly an awesome solution if all works as expected...I can feed the camp battery from the Rivian when it's outlets are on or via solar if we are camping in one spot for a while, and it can keep the 12v battery tended without the HV>12v recharger ever lifting a finger. Unless of course I need to steal the camp battery from it's usual buckled-into-the-back-seat home to power our tent heater and/or electric fridge (in the truck bed), at which point it would be lovely if the Ohmmu has the reserve capacity to keep the computers off for at least overnight.

 

[Singletracker]

For the single battery R1s I am going to do a test with feeding the charge into the 7 Pin Trailer plug. https://www.amazon.com/gp/product/B0CMDJRBDB/

I’m waiting for the results. As I understand it, one could connect a charger to the pigtails by the trailer hitch to maintain the single battery on my ‘23 R1T. Using a 7 pin adaptor to the trailer plug would be even cleaner.

 

[josh0]

I got the actual dimensions of the Lensun solar panel for the Rivian hood. We could definitely fit something larger, but I’m not sure anyone makes anything of proportions that would look better. Strongly considering buying one to test out.

 

[SSteveEV]

That was my reaction when I first heard the figure. I made sure that I heard it correctly by replying "I'm sorry, did you say 12%?" and "Do you mean a 12% daily loss?" The answer was yes, up to twelve per cent (12%) is considered to be within normal daily SOC loss limits. As I posted, I have to think this can't possibly be accurate as a routine, daily, to-be-expected SOC loss.

They once told me 10%. If they ever say something like that again I'm asking for that spec in writing on Rivian letterhead.

 

[shap]

I think the formal statement is 2% per 24 hours, that is huge IMHO. This was confirmed by Wassym Bensaid on his last call. Anything above 2% - you can open a ticket and challenge Rivian support. But as far as I see - most of GEN1 cars are averaging between 1% and 1.8% per 24 hours.

For a long time, we suspected that charging a 12V battery is what caused this drain. I think this thread is confirming that.

 

[PBRAZ]

I think the formal statement is 2% per 24 hours, that is huge IMHO. This was confirmed by Wassym Bensaid on his last call. Anything above 2% - you can open a ticket and challenge Rivian support. But as far as I see - most of GEN1 cars are averaging between 1% and 1.8% per 24 hours.

For a long time, we suspected that charging a 12V battery is what caused this drain. I think this thread is confirming that.

Glad I found this message and confirming this may be true. Vampire drain was never an issue for me - maybe 1% every 2 to 3 days - until my vacation last week where the car sat at home for 6 days, unplugged at 72% SOC. From the app I could see it was losing 1% a day, which I thought was strange. Came back from vacation (65% SOC) and charged it with no issue. Drove it for a day, then it sat for two days at around 70% SOC and seemed fine...until today when I went to unlock it and the Service 12V Battery notification popped up on the app; the car was completely dead. Jump started it through the trailer hitch which got the doors to unlock and screens to come on, but charge port door and frunk would not open via the external buttons or through the app (greyed out). Towed to the SC and I'll see what they say tomorrow.

A few things of note:

- When I plugged it in after coming back from vacation, the car started charging immediately despite it having a schedule set for later that evening. The vehicle had never charged outside of its schedule before. It did stop after like a minute then proceeded to charge normally later that night during the schedule.

-When I got back from vacation the vehicle was down to its bump stops in the front, but fine in the back.

-When I jump started the car only the driver side windows would go down.

Sponsored