Vampire Drain 0.2%/day.... Essentially Zero?

[BTOR]

I had a situation were I wasn't going to be using our 2025 R1S Dual Max for 27 days (May 1 - 28, 2025). It was parked in our garage during this period. On May 1st I drove it down to 1% SOC. The display showed an estimated remaining range of 5 miles when I parked it. My goal was to be at zero when I pulled in to the garage. Oddly though, my actual distance of travel was 1.7 miles for every estimated mile remaining. When I started the process it said estimated remaining range of 12 miles. After driving 12 miles, it said ~ 6 miles of range remaining. Being short on time, I headed for home. When I pulled in my garage it was at 1% and 5 miles of range remaining (see pic).

I proceded to charge to 100% SOC @ 48 A, 11.7 kW. Charging was completed shortly after 1:00 AM on May 2nd. The vehicle was unplugged at 8:00 am on the 2nd. The wall charger said it delivered 133.8 kWh. The Rivian App shows 110 kWh. Not sure if the difference is due solely to line loss (heat) or perhaps charging the 12 V as well and the Rivian App only shows what the HV battery accepted. However, if the Max battery pack has 142 kWh of usable energy, I would have expected the Rivian App to show close to 98% or 99% of 142 since my SOC was 1% when the charging started.

Vampire Drain: When I drove our R1S yesterday (May 28th) the SOC was 95% (see pic). So over those 27 days, it only loss 5% SOC. My BKM (Best Known Method) when I park the vehicle is:
- Turn off HVAC
- Turn off Radio
- Turn off Display(s)

I'm not sure if that BKM makes the difference but IMO, 5% loss over 27 days is essentially zero. I would have been happy with 1%/day. But 0.2%/day is exceptional and almost to good to be true !


By the way, I was away from home during this period (oversea travel). I typically see ~ 0.8%/day when at home using the same BKM each time I park. I use my phone as my key.

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[Las_Vegas_R1S_Tri]

I owned a Tesla Model S from 2017 until 2021. It had a 3% per day vampire drain the entire time that I owned it.

 

[portdirect]

I've found the drain to be very temperate related - around 65-75f it becomes totally negligible with gear guard etc turned off. Whist at 25f it will loose 2-3% a day under the same conditions; ive not yet had the opportunity to test the other end of the extreme (ie over 100f) recently.

 

[BTOR]

I owned a Tesla Model S from 2017 until 2021. It had a 3% per day vampire drain the entire time that I owned it.

Wow, that is quite high and as such, costly. I’m sure electrical rates in Vegas are much more than what we pay in Oregon.

What are you currently experiencing with the R1S?

 

[BTOR]

I've found the drain to be very temperate related - around 65-75f it becomes totally negligible with gear guard etc turned off. Whist at 25f it will loose 2-3% a day under the same conditions; ive not yet had the opportunity to test the other end of the extreme (ie over 100f) recently.

Our garage never dips below 40° in the winter and generally never gets above 80° in the summer. So even though there’s a 40° temperature swing, the vehicle will never experience extremely cold/hot temperatures while parked in our garage.

As the weather has turned warmer, I’m experiencing a pleasant bump in my efficiency. I think most of that came after one of the more recent software updates. But I’m sure temperature has also factored in. I’m consistently getting over 4 miles/kWh where several months back it was upper 2’s to mid 3’s.

Generally, what I now see is my expected range at the end of a trip equals the start range minus the number of miles driven. For example, if at the start of an 100 mile trip, if my range is 300 miles, then at the end of the trip it says 200 miles. Before, the end range would always be 15% to 20% less, so in this example ~ 180 miles. And the math works too. If I multiply kilowatts used by efficiency, the mileage worksout.

 

[Ceejay]

Is the low level of vampire drain associated with it being a gen 2 vehicle vs gen 1?

 

[Las_Vegas_R1S_Tri]

Wow, that is quite high and as such, costly. I’m sure electrical rates in Vegas are much more than what we pay in Oregon.

Rates in Vegas are around 0.13

(100kw battery) x (charged to 90%) x (3% drain) = 2.7kw x (0.13 electric rate) = $0.35 per day (is my math correct?)

 

[Mathme]

I'm still stuck on why charge a Max Pack to 100% and then proceed to leave it charged at that state for a month while away as that's really hard on the battery. Lithium batteries like to live between 20-80% and will last way longer if kept for long durations between those percentages.

If you really want to be nice to your battery, leave it plugged into a Level 1 outlet and set your charge level to 50%....

 

[ndmiller]

This is my 3rd EV and I haven't a clue about battery drain, never looked, don't care. Still can't believe these threads keep getting posted, there is no such thing as vampire drain, it's made up. Either the battery is self-discharging as all batteries do or something in the device is using the power.

From the internet
Batteries inherently lose charge over time, even when not in use, due to a process called self-discharge. This is a natural consequence of the chemical reactions that create electricity within the battery. Factors like temperature, age, and the state of charge also influence the rate of battery degradation.

 

[BTOR]

I'm still stuck on why charge a Max Pack to 100% and then proceed to leave it charged at that state for a month while away as that's really hard on the battery. Lithium batteries like to live between 20-80% and will last way longer if kept for long durations between those percentages.

If you really want to be nice to your battery, leave it plugged into a Level 1 outlet and set your charge level to 50%....

Primary reasons:
From what I’ve read and been told by RIVIAN, it is recommended to do a full charge periodically. I hadn’t done one since the beginning of Feb. This calibrates the battery ECU and balances the multi cell battery packs.

Secondary Reason:
Gave me a reason to run some experiments, primarily Phantom drain.

99% of the time my vehicle sits between 30%-70%, lithium -ion battery sweet spot. But similar to my other lithium ion battery operated devices, I do a full discharge and charge periodically.

 

[BTOR]

This is my 3rd EV and I haven't a clue about battery drain, never looked, don't care. Still can't believe these threads keep getting posted, there is no such thing as vampire drain, it's made up. Either the battery is self-discharging as all batteries do or something in the device is using the power.

From the internet
Batteries inherently lose charge over time, even when not in use, due to a process called self-discharge. This is a natural consequence of the chemical reactions that create electricity within the battery. Factors like temperature, age, and the state of charge also influence the rate of battery degradation.

Well that is the whole point. When the vehicle is not in use, nothing should be using and draining the batteries. So if you do have energy loss, something may not be right. And if it is significant, it is costing you real money.

If it is just normal battery drain then it should be the essentially the same across all vehicles with identical battery packs when the vehicles are in the same idle state . What we’ve seen from communication in this forum, it can vary significantly (<1% to > 8%).

IMO, this warrants further understanding, discussion and sharing of BKM’s.

If you are an owner and a driver of EV’s, that doesn’t care then Kudo’s to you

 

[Riviot]

Primary reasons:
From what I’ve read and been told by RIVIAN, it is recommended to do a full charge periodically. I hadn’t done one since the beginning of Feb. This calibrates the battery ECU and balances the multi cell battery packs.

The internets recommend that... But you forgot the part about not leaving it at high SoC for very long. Discharge as soon as possible.

Also, Rivian only recommends the below:

 

[DayTripping]

I'm still stuck on why charge a Max Pack to 100% and then proceed to leave it charged at that state for a month while away as that's really hard on the battery. Lithium batteries like to live between 20-80% and will last way longer if kept for long durations between those percentages.

If you really want to be nice to your battery, leave it plugged into a Level 1 outlet and set your charge level to 50%....

I'm with you on this one. As I was reading the original post, I was thinking to myself, OMFG. About the 2 worst things you could do to a max pack. Icing on the cake would be if it was hot in the garage to top it off. Probably just did more wear on that battery than I did on my Teslas in 3 years. How you use the battery the first year really seems to set the tone for the outlying years as well from what I've seen.

They didn't need to top off to check vampire drain anyway. Just invest in something like Electrafi.

I am still sort of stunned. Almost an entire month at max charge level. I would have been praying for vampire drain to bring my charge level down and running my AC/heat to do it.

This isn't a great analogy, but it sort of makes the point. Keeping your battery at 100% or close to it, is like revving your ICE motor to redline and keeping it there. No imagine your ICE motor kept at redline for a month...

There is almost nothing that could have been done to degrade that battery pack faster than maybe doing the same and parking it in the desert, so there were very high temps to go along with it. Maybe if the garage was very cool, it might have limited the damage.

Here is an easy read that will help others who want to minimize degradation.
https://batteryuniversity.com/article/bu-808-how-to-prolong-lithium-based-batteries

 

[mkhuffman]

Is the low level of vampire drain associated with it being a gen 2 vehicle vs gen 1?

Yes, this appears to be the case.

I have only had my T for about 3 months, but lately I have had the opportunity to monitor vampire drain. Since the truck is new, and the 12V is new, this is the perfect time to see how the truck behaves before the 12V gets tired and needs more help from the HVB.

I usually park in the garage and often leave the truck plugged in. I am replacing one of my garage door openers, and that project is taking a lot longer than I expected. Anyway, my truck has been sitting in the driveway, unplugged.

Over a 12-hour period, the truck slept the entire time. Here is the Electrifi report:

I am not sure if the HVB really lost 0.5%, or if that is just normal variations from the BMS as it approximates the total charge on the HVB. Other sleep cycles show zero SOC loss.

Regardless, the loss is really best in class for a BEV. My Mach-e would do something similar, and after sitting for a week the SOC was usually exactly the same as when I parked it. Maybe slightly less, but essentially the same.

At home I have Gear Guard and proximity locking turned off. Those two items seem to make a huge difference because there is much more significant vampire drain when I travel (2-3% overnight).

I am going to turn Gear Guard off and see what happens when I travel next week. Hopefully proximity locking does not cause any significant vampire drain. It didn't in my Mach-e.

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