Any tests done on Vampire battery drain?

[Craigins]

Man, all these people saying they can leave their cars at the airport for over a week are making me jealous of airport parking prices.

Anything over like 4 days here is cheaper to take a taxi.

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[eaa56]

I tested vehicle shipping! Tldr; doesn't help.

I did notice the fan (BMS?) didn't randomly kick on as much, it was slower to unlock, and the screen didn't wake as quickly as normal. So maybe this would be better tested over a longer timeframe.

24 hour difference: 3%, 4kWh, 10 Conserve miles

Would be helpful if someone could do a longer test of the transport mode to see if the rate of loss decreases over the course of several days (or more).

 

[Riviot]

Would be helpful if someone could do a longer test of the transport mode to see if the rate of loss decreases over the course of several days (or more).

I shouldn't need to drive again till Thursday morning, I should be able to do a longer term test starting tonight after my charge finishes.

 

[Ralph]

I will, again, remind you all that Tesla has not "fixed" this in as long as they have been making cars.

And yet a Polestar owner above reports he doesn't experience excessive drain. How can this possibly be?

 

[DJG]

And yet a Polestar owner above reports he doesn't experience excessive drain. How can this possibly be?

It's the same as the charging throttling due to temps. They are trying to manage battery temps within too strict parameters. The fix will be loosening those as they get more comfortable.

Anyone received 2022.15 yet? Wonder what else will be in it besides the garage opener.

 

[ajdelange]

And yet a Polestar owner above reports he doesn't experience excessive drain. How can this possibly be?

The question illustrates what's been bothering me throughout this thread. People don't understand what phantom drain is nor, therefore, what causes it and what can be done to ameliorate it. So what is it? Phantom drain is ANY drain from the MAIN battery which occurs when the gear lever is in any position other than D or R. Thus if you are in P with the A/C on you are incurring phantom drain (and quite a lot of it) from the air conditioner (it's compressor is connected directly to the main battery). If you are parked somewhere in the woods miles from town with everything "off" you incur phantom drain when all the receivers (key fob, GPS...), presence sensors, modems, clocks, timers, diagnostic loops etc run the 12v batteries down to the point where the dc/dc converter charges them. During that charging time you draw phantom power from the main battery.

So how do you prevent/reduce/mitigate phantom drain? You reduce, minimize or eliminate those background task loads. You don't log battery voltage every 30 sec; you log it once a minute. You don't check in with the mother ship every minute, you do it every 2, You don't check for the proximity of the key fob continuously, You do it every 5 seconds. When the owner approaches the car you don't flash lights and open the driver's side door for him. You don't code evaluation of a*x^3 + b*x^2 + c*x + d as such but rather as ((a*x +b)*x +c)*x + d etc.

Obviously the Polestar isn't doing as much in background as the R1T. In simple terms that's all there is to it. if you tell me that the Polestar is doing just as much background stuff as the R1T but still doesn't have any phantom drain then I'll tell you it is violating physics.

 

[DJG]

The question illustrates what's been bothering me throughout this thread. People don't understand what phantom drain is nor, therefore, what causes it and what can be done to ameliorate it. So what is it? Phantom drain is ANY drain from the MAIN battery which occurs when the gear lever is in any position other than D or R. Thus if you are in P with the A/C on you are incurring phantom drain (and quite a lot of it) from the air conditioner (it's compressor is connected directly to the main battery). If you are parked somewhere in the woods miles from town with everything "off" you incur phantom drain when all the receivers (key fob, GPS...), presence sensors, modems, clocks, timers, diagnostic loops etc run the 12v batteries down to the point where the dc/dc converter charges them. During that charging time you draw phantom power from the main battery.

So how do you prevent/reduce/mitigate phantom drain? You reduce, minimize or eliminate those background task loads. You don't log battery voltage every 30 sec; you log it once a minute. You don't check in with the mother ship every minute, you do it every 2, You don't check for the proximity of the key fob continuously, You do it every 5 seconds. When the owner approaches the car you don't flash lights and open the driver's side door for him.

Obviously the Polestar isn't doing as much in background as the R1T. In simple terms that's all there is to it. if you tell me that the Polestar is doing just as much background stuff as the R1T but still doesn't have any phantom drain then I'll tell you it is violating physics.

I think people understand just fine what it is, the question is centered around what is the Rivian doing that all the other EV's are not to incur such draws on the battery. My EV does not incur any vampire drain that can be measured over the course of several days, perhaps you could given a week or two but I've never seen it.

Most of the time it's being measured/stated in terms of %, but really it should be reported in terms of energy/power/kwh. Given the size of the pack is much larger than any other EV being compared, the power used for normal background functions should actually be LESS % of the battery (more or less it should require the same power to unlock doors, connect to HQ regardless of vehicle). For example, when someone reports a daily loss of 4%, compared to 1% or less for a M3 or P2, it really means that it's more like 8x the power draw because the battery is nearly twice as large. Some have taken that step to show the math of it equating to an average continuous draw of 200w.

I doubt fairly simple things like locking/unlocking, logging battery stats, etc would draw that much power, so I'm convinced it's BMS related, as most have noted the fans running a lot.

 

[Ralph]

....snip

Obviously the Polestar isn't doing as much in background as the R1T. In simple terms that's all there is to it. if you tell me that the Polestar is doing just as much background stuff as the R1T but still doesn't have any phantom drain then I'll tell you it is violating physics.

Agreed.

And surely it is oblivious that the problem people are experiencing, trying to isolate, and then describe is, the same as you - unmanaged background tasks. For example, people have proven that although Gear Guard is off the cameras continue to generate heat. Do Tesla vehicles do this? Have they solved for this problem?

My point? It is then not particularly insightful or helpful to post every few days or pages (paraphrasing), "Years on, Tesla has not solved this problem, so no one can." Those comments, unlike what you have now posted, don't advance the discussion.

I think it can be argued that Tesla, Polestar, and perhaps others have been more successful than Rivian at managing the background tasks that you acknowledge are the reason for the problem being discussed.

Again, few, if any believe that all drain over time can be eliminated. What they are trying to understand and minimize is drain from those background processes that can be managed better. This is particularly important for some use cases such as airport parking and "adventure".

Sorry for the rambling and what may be perceived as an "argumentative" tone. But the, "If Tesla hasn't done it, no one can." bs gets old.

 

[ajdelange]

I think people understand just fine what it is, the question is centered around what is the Rivian doing that all the other EV's are not to incur such draws on the battery.

If in fact they did they would have no trouble understanding that a vehicle with less phantom drain is simply doing fewer things in sleep than another with more or doing them more efficiently.

My EV does not incur any vampire drain that can be measured over the course of several days, perhaps you could given a week or two but I've never seen it.

Then your EV is indeed OFF. it is doing NOTHING when parked. As that violates physics (or chemistry - all batteries are subject to some self discharge even though it be but a percent or so per month) your second hypothesis is true (you didn't observe long enough or the resolution of you meter is inadequate).

but really it should be reported in terms of energy/power/kwh.

True

an average continuous draw of 200w.

Yep. The average phantom draw for my X is just under that - about 167 watts, At least that's what I must replace nightly when I am not driving the car. There is nothing "wrong" here. I can sacrifice things if I want to get it lower but I don't care. The juice is free anyway.

The valid complaint to levy against Rivian is that they haven't, as yet, made the option to forego some of the offline loads,

I doubt fairly simple things like locking/unlocking, logging battery stats, etc would draw that much power, so I'm convinced it's BMS related, as most have noted the fans running a lot.

Think what you will but is has occurred to me that equalization may be involved. To do that one must either bleed off (wasting energy) any series cell group that is a higher voltage down to the voltage of the lowest or transfer from over charged groups to under charged ones. This is an active process (e.g. "flying capacitor") and therefore less than 100% efficient also causing loss. But wouldn't one do equalization at or just after charging rather than during sleep?

 

[ajdelange]

Sorry for the rambling and what may be perceived as an "argumentative" tone. But the, "If Tesla hasn't done it, no one can." bs gets old.

The point in bringing up Tesla over and over again is that it is a fairly well established manufacturer of BEVs and, despite people's winging about phantom drain (which they certainly did) their is some which is a result of these background processes doing things which the customers want done and/or things that Tesla thinks need to be done. IOW, phantom drain is the result of design trades.

Give Rivian time to understand their creation better, refine the requirements and attune themselvs better to their market and the phantom drain situation will change.

 

[Rousie13]

And yet a Polestar owner above reports he doesn't experience excessive drain. How can this possibly be?

We currently have two XC40 Recharges and have NO excessive vampire drain on either car. They also do not nearly have the number of features like our Tesla did (sentry, phone as key, etc).

 

[DJG]

If in fact they did they would have no trouble understanding that a vehicle with less phantom drain is simply doing fewer things in sleep than another with more or doing them more efficiently.

Again, they do understand that something is drawing power to a larger extent in the Rivian, but we don't know what. Is it something we can mitigate through settings, is it something Rivian can mitigate through software, is it poor hardware/design that can never be mitigated?

The discussion is not about why is there phantom drain, it's about why is it more in Rivian than in any other EV (by a extreme margin).

I didn't mean to imply mine has none, but my EV (eTron) has less because it is a) less "connected" (doesn't even have ability for OTA, so it just doesn't connect to anything regularly) and b) isn't managing battery temps when not plugged in (have never heard fans or cooling/heating systems). But yes, it does have some, it's just measured in a fraction of a % (of a ~85kwh battery) per day and I can only see in full % increments. Put it this way, if you told me I had none, even though technically false, I would believe you. It's that miniscule. But like you say, that's not good or bad, it just speaks to what it is not doing vs. what other vehicles are.

A test I'd like to see, but not sure if temps still allow for it, is to see what efficiency an R1T gets when driven "cold" after sitting overnight without charging. If it gets close to "normal" efficiency (could be compared by doing the same drive again but after charging and heating the cabin) over a relatively short drive, it would support the hypothesis that it is actively preconditioning even when not plugged in. In my vehicle, I would plug in and charge on a timer to conclude before departure, which makes a significant difference in efficiency. Who knows, this could be why the UI doesn't have the option to schedule charging to complete by a specified time for efficiency sake, because the BMS is always keeping things in optimal conditions.....

 

[Riventures]

Since Tesla and Polestar have been mentioned, I'll throw in Audi eTron data:

My eTron does not lose any charge just sitting around, and it does sit around for 3-4 days on a regular basis. However, it has a regular 12V battery similar to an ICE car, and apparently if the car is not driven for a couple of months that may deplete, which causes a bunch of problems. The main battery does not drain though, which is a good thing.

So, BMS differs from one manufacturer to another, Audi and Lucid seem to be ahead of other manufacturers when it comes to thermal management of batteries. I am not sure if this has anything to do with the phantom battery drain when idle.

 

[ajdelange]

The discussion is not about why is there phantom drain, it's about why is it more in Rivian than in any other EV (by a extreme margin).

Not the case at all. My X LR+ uses 4 kWh/da (but has measured as high as 8 kWh/da but that's obviously the result of measuring in a short window during or near a 12V battery charge). And I know what it is from - comms.

 

[DJG]

Not the case at all. My X LR+ uses 4 kWh/da (but has measured as high as 8 kWh/da but that's obviously the result of measuring in a short window during or near a 12V battery charge). And I know what it is from - comms.

Interesting, but seems to be an outlier vs. other Tesla owners (albeit mostly M3) that only see 1% or less per day (less than 1kw). Is there a difference in comms between 3 and X to that extreme?

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