Went on a small road trip today with the inlaws to my wifes grandparents. Of course everyone was excited to go in the new Tesla, I just had to hide my range anxiety for my first road trip. High temps today were around 35 F, and we left after charging to 100% (256 miles) drove 9 miles to pick up the inlaws, Drove 78 miles to her grandparents and had 143 miles "left "in the tank". I was worried about phantom drain, but convinced myself that if I didn't check my app and wake the car that we'd be fine. After about 4 hours we packed up the car and all packed in to head home and I was ready to explain to everyone why we might have to stop on the way to charge, but sure enough the screen said we still had 142 miles of range … awesome! followed the GPS back to the inlaws and ended up with the predicted 18% SOC, and then 15% after the 9 mile drive home. All in all I'm pretty pleased for a winter drive of 180 miles without having to charge at all during the day.
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Mid Range trip (low phantom drain)
- Thread starter sraatc17
- Start date
Alpaca
Member
Nice - and at cold temps ! I am going to try my first roadtrip Friday - 121 miles each way - plan to do one supercharger stop for insurance 
intenost
Member
Cool, we took our LEMR out for the first real road trip since delivery on Dec 12. Went great.
Also in MA and it was a reasonably chilly day (mostly low 30's and into the 20's on the return leg), so I was interested in how the cold would affect range. I did warm up the car before we left.
Left with a 90% charge. We had the heat set to 65 and the seat heaters on and it was better than I expected (~88% efficiency per Teslafi.com -- details below). Drove at or slightly above posted speeds.
Headed out from Acton on Rte 2 West to Amherst/Northampton, stopped there, and later went south on local roads to the Mass Pike East, and swung back up on 290 & 495 back to Route 2. So mostly highway, but some time on slower secondary roads.
We hit the Auburn supercharger for a top-off but didn't need to - we'd have very comfortably made the 161 mile trip without it. I wasn't sure if we'd comfortably make the round trip when we left, and I had never supercharged before, so I wanted to get that stop in. Charged for 15 minutes and left. Nobody else there.
Got pretty comfortable with autopilot it worked well although we were a little uncomfortable how it wanders over to the right when passing an exit. We got used to it. Also I'm still trying to figure out exactly how it deals with speed limit changes, need to read some more about that.
And I was surprised on the way back -- at dusk -- it turned the high beams on automatically -- and turned them off when a car approached or it felt the high beams were not needed. Pretty cool. But I thought the notion of auto high-beams was that you turned them on and the car switched them off when another car approached. Live n learn. Need to dig into the manual.
Here are the key stats:
Total Miles Driven
161.78
Rated Miles Used
183.15
Efficiency
88.33 %
kWh Used
41.29 kWh
Wh/Mile
255 Wh
Average Temp
25.55 F
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Nice! I didn't really think fast enough to actually record all of my data, and haven't set up teslafi yet because I wasn't sure about the sleep settings and didn't want it to keep the car awake all the time.
I forgot to mention that I am currently on the EAP trial and only used it to show it to my father-in-law. We were driving from Belmont to Belchertown, so mostly on the pike driving with TACC on set to 69 and I'll say that is a feature that I will definitely miss when the trial is over. But I just don't think it's worth 5K.
I forgot to mention that I am currently on the EAP trial and only used it to show it to my father-in-law. We were driving from Belmont to Belchertown, so mostly on the pike driving with TACC on set to 69 and I'll say that is a feature that I will definitely miss when the trial is over. But I just don't think it's worth 5K.
StealthP3D
Well-Known Member
Nice!
My experience with our two LR Model 3's is that phantom drain is minimal and only worth thinking about if you are, for whatever reason, pushing the range to the last few percent of battery power or parking for multiple days away from the grid. If you use the car normally and daily, you don't even need to think about it.
intenost
Member
We drive through Belchertown on our way home, heading for the Pike.
I set up Teslafi with sleep enabled (all other settings at default) and so far so good the car is sleeping for long periods (currently asleep for 11 Hours 36 Minutes) so it doesn't seem to be a significant contributor to vampire drain.
AlanSubie4Life
Efficiency Obsessed Member
Yes, typically for short trips like this you won’t have to worry about phantom drain, unless there is something stopping the car from sleeping (which happens but is rare and sometimes user error, sometimes software issue).
When everything is working normally, think of phantom drain as 5-10% added to your electricity cost of running the vehicle, if you drive about 12000 miles a year. It’ll be a smaller percentage hit if you drive more, larger if you drive less. For example, if you drive only 6k per year, it increases energy use by 15%. When calculating cost of ownership/budgeting you need to add this extra cost to the window sticker MPGe (or kWh/100 mi) numbers (as well as other climate-related additions/corrections ).
When everything is working normally, think of phantom drain as 5-10% added to your electricity cost of running the vehicle, if you drive about 12000 miles a year. It’ll be a smaller percentage hit if you drive more, larger if you drive less. For example, if you drive only 6k per year, it increases energy use by 15%. When calculating cost of ownership/budgeting you need to add this extra cost to the window sticker MPGe (or kWh/100 mi) numbers (as well as other climate-related additions/corrections ).
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StealthP3D
Well-Known Member
"Phantom drain" refers to the loss of energy caused by the vehicles hidden overhead. It does not include use of the headlights during ingress and egress, charging losses due to the fact that no charger is 100% efficient, pre-heating the cabin or losses between the electric meter and the charge port. It also does not include "faux phantom drain" which is not a loss of energy, merely an inaccuracy of the BMS's estimation of remaining energy in the battery. It's important to know that the estimate of remaining miles (or % state of charge) is only an estimate and cannot be all that precise in all conditions due to limitations with how the state of charge is measured. batteries are electrochemical devices and the "chemical" part of the battery is what causes difficulty in the precise measuring of the state of charge. In other words, some phantom drain is not actually drain. It's truly phantom (a figment of the BMS).
I only drive 9,000 miles/year and yet my phantom drain is much less than 5-10%.
In any event, with electricity retailing for about 10-15 cents/kWh, I can hardly get upset about losing a few kWh's here and there. Compared to filling a gas or diesel tank, it's not even a hill of beans. The Model 3's are so much cheaper to operate than our previous Volvo and Mazda I just don't know why anyone would care, especially when that loss is largely unavoidable. There is going to be a small amount of phantom drain and a small amount of charging inefficiency no matter what. Taking all the losses into account, it's still multiple times better/cheaper vs. ICE.
AlanSubie4Life
Efficiency Obsessed Member
Agreed. My numbers were based on 2.4 rated miles per day which is “about average”. This does not include any of the items above; it’s just a typical number for true standby losses, which may be somewhat high or lower than the actual number, and may go down with time as Tesla optimizes. Fortunately the MPGe does include the charging losses. It’s true that some of the apps seem to incorrectly account for cold weather battery “losses”, which aren’t actually losses.
Of course as far as energy efficiency goes, electric drive is still better than ICE solutions.
The only reason I care about this is that it isn’t actually needed (as we have discussed before), and the drain largely serves no useful purpose (other than wearing out the 12V AGM battery). It’s the engineer in me, I guess. Pretty sure it will be improved by Tesla with time. They’re just in triage mode right now. Once they get the door panels on straight, FSD beta is out, paint issues sorted out, they’ll probably circle back. Things are gradually improving...
Curious, how are you tracking this?
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StealthP3D
Well-Known Member
It's not clear how you came to the conclusion that the phantom drain serves no useful purpose. Clearly, at a minimum, some of the phantom drain serves necessary functions. And if you want to compare it to other EV's like the Bolt that has lower phantom drains, I don't think it's a fair comparison for multiple reasons. Two of which are:
1) The Model 3 has a longer range and more battery capacity. So, driven equal amounts on average, of course there will be higher phantom losses with a bigger battery (because phantom losses include the battery self-drain losses).
2) None of us are privy to all the uses Tesla makes of electricity when sitting idle. Clearly, Tesla's have superior battery longevity. Some of the losses could be used to mitigate battery degradation, we simply have no way to track where the losses are coming from.
We installed a separate 200A electrical service for charging our two Model 3's.
AlanSubie4Life
Efficiency Obsessed Member
I said largely..not *no* purpose. Certainly a few (2-3) watts seems reasonable given the various LTE and Bluetooth functions that are operating. It’s true that we don’t know what, if any, conditioning Tesla does at 60 degrees. I suspect that nothing is done though.
And it is absolutely true that I don’t KNOW that the energy is largely wasted. It is just my strong suspicion; I could definitely be wrong.
To my knowledge, self drain of Li-ion is pretty negligible. But, we actually do know (or could know) that the numbers are not HV pack self-drain driven. When in sleep mode, the contactors are disconnected. During this time all the losses must be drawn from the 12V battery, AFAIK. I believe this drain has been measured on a Model S, but similar experiment should be done on a Model 3. So, if we could quantify that, then we would know how much the true sleep mode drain is.
We don’t seem to know what the sleep mode losses are, exactly, without that information. Because as far as I can tell none of the apps actually report this, even if they purport to (based on what @rawmean has said about the availability of this info in the API). Some apps seem to use battery state info at the beginning and ends of idle periods to infer the sleep mode losses (and Stats specifically only provides the idle mode losses (which are equivalent to total phantom drain) due to the the API limitation as I understand it).
Anyway, the reason I mention sleep mode is that I think we can agree to the extent there are losses there, they have nothing to do with conditioning - because the HV battery is disconnected.
I guess we will find out as time goes by the extent to which I am right; I expect things may get better with time!
Re: your tracking. I understand your separate service would give you exact total usage, but without careful tabulation I can’t come up with how I would use this to infer vampire/phantom losses, even if the charging were entirely at home. Maybe I am being dumb. It seems like it would be hard to separate it out? You could certainly compare to the lifetime kWh usage trip meter in the car to determine how much of the input energy made it to road & other functions, while car was not in park. And get a measure of efficiency that way (but the loss component would be the sum of charger loss, service connection loss, phantom, idling losses when sitting in park, etc.).
StealthP3D
Well-Known Member
Self drain of Li-ion is pretty low on a per cell basis. But since there are 75Kwh worth of cells, it can add up when you consider most people only use around 25% of that each day. Some average a lot less than that.
That's a very relevant point you bring up about all consumption when the contactors are open being drawn from the 12V battery. This is done (I believe) to prevent a constant, steady draw on the HV pack (and also because all the low voltage functions are set up to draw from the 12V battery anyway). What I've noticed is the 12V battery is charged around 5 times/day (rough guess and depends upon usage). There is considerable inefficiency drawing from and charging an AGM lead-acid battery. So, any low voltage consumption, even when the contactors are closed, must deal with the inefficiencies of the 12V battery charger and any low voltage consumption when the contactors are open must additionally deal with the inefficiencies of charging/discharging a lead-acid battery, not a very efficient operatiion. Also, for whatever reason, Tesla decided to charge the lead acid battery at 15.3 volts. That's about 0.5V higher than typical for optimum AGM lead-acid battery charge voltage. I imagine Tesla has a reason for this but I have no idea what it is.
I tend to think Tesla crunched the numbers and determined it was better to sacrifice some overall efficiency to do everything in their power to extend the useful life of the HV battery (even sacrificing the life of the lead acid battery in the process). And I'm not convinced we know everything they do to make the batteries last so long, even in some pretty harsh climates.
That's true, it only tracks total consumption which we can compare to our combined Wh/mile and miles driven from time to time. My impression that we have very low vampire drain comes mostly from the fact that my car is often parked for three days at a time, sometimes longer, and it typically only loses about 1 mile/day. Sure, I've seen up to four miles/day reported but that is when the battery is put away warm and left to cool. I've also seen it GAIN up to two miles in one day. So I don't put a lot of faith in those 16-20 hour periods when it APPEARS to lose 2-4 miles since it's always less than that when parked for longer periods.
I think a lot of the freaking out about "vampire drain" is simply the result of people who are enthralled with their new high tech marvel checking up on it more than they know. Most people have a spouse who has the car on their phone too. They are probably checking up on it too. There's a lot we don't know. The headlights come on every time the door is opened. We know kids love Tesla's too. They are probably visiting the car when no one is looking. And then there are 3rd party apps. I don't know if people actually have them configured to never wake the car up or if they just think they do.
I have to go with my observation of our two Model 3's, both of which have less than 1% drain when parked and left undisturbed. We don't have kids, third party apps and my wife is not the curious type. She only wakes it up when she needs to go somewhere.But, yeah, the more the car get "woken up" the more vampire drain you're going to see.
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