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Battery Drain Overnight.

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Do you have sentry mode turned on?

Did you use the app a few times to check the car?

Anything that wakes the car up can cause it to use power. When awake, whether with sentry mode running, or for some other reason, the car systems will use around 200 W to 300 W of power from the battery. When asleep, the drain from the HV battery is zero, as the main contactor opens to isolate it, and any remaining drain comes from the 12 V battery. If that gets low, the car will wake up and use the main HV battery to charge the 12 V battery.
In that case a bad 12v battery could keep waking the car to charge it? Thus creating a drain?
But should be unlikely on a new car, maybe a car 3/5 years old or more...
 
In that case a bad 12v battery could keep waking the car to charge it? Thus creating a drain?
But should be unlikely on a new car, maybe a car 3/5 years old or more...

Yes, it could, but as you say, it's pretty unlikely on any UK Model 3, as none are very old yet.

The way the systems work is that when the car goes to sleep the HV battery disconnects and is isolated (if you are within earshot of the car when it does this you can hear the clunk from the contactor opening). From then on, the residual stuff that is always on (listening for an SMS via LTE, running the background stuff like software timers, car alarm etc and sensing a change in the charge port CP line) is powered only by the 12 V battery.

If the 12 V battery voltage drops, or the car is woken up for any reason (using the app, using any other intrusive bit of software that wakes the car to get data, unlocking the car or a routine "phone home" to the Tesla Mothership) then the car will close the HV contactor, and power on the main systems, including the 12 V DC - DC converter that charges the 12 V battery. In the awake state the car uses a surprisingly high amount of power, 200 W to 300 W, as pretty much everything seems to get powered up, as it would be when driving. It's this relatively high power demand when awake that tends to cause most of the reported vampire drain, and is the reason that doing anything to minimise the number of times the car wakes up, or stop it staying awake by turning off features like sentry mode, makes a big difference.
 
In that case a bad 12v battery could keep waking the car to charge it? Thus creating a drain?
But should be unlikely on a new car, maybe a car 3/5 years old or more...

My last ICE car was fantastic to drive, but had 12v battery issues, which was quite common for that early model Alfa Romeo. Most people seem to think it was an “intelligent” battery management system causing the issues. I had all kinds of things done to fix it under warranty, including a new battery.

I had the Alfa for a few months alongside the Tesla and I used to plug the ICE car in to charge more than the Tesla.
 
Looks like I need to start monitoring the car. What’s the best software to do this?
Teslamate IMHO is the best for details and easy to use graphs, but is a bit technical to install. Teslafi is easy to install but has a funky interface that again IMHO is harder to read. Teslamate is free, Teslafi costs about a fiver a month, but you can use it for 2 weeks for free. That might be enough to see what's causing you issues.
 
Teslamate IMHO is the best for details and easy to use graphs, but is a bit technical to install. Teslafi is easy to install but has a funky interface that again IMHO is harder to read. Teslamate is free, Teslafi costs about a fiver a month, but you can use it for 2 weeks for free. That might be enough to see what's causing you issues.
I think I’ll check Teslamate out. Thanks for the help
 
Looks like I need to start monitoring the car. What’s the best software to do this?

TeslaFi is hosted and maintained for you (ie <5 minutes to setup and just works from there on) and costs £35-40/year ($5/month/$50/year) less any referral credits you get. Ask any TeslaFi user for a referral code for an extension to the 2 week trial.

TeslaMate is free but you have to host and maintain yourself - various options RaspberryPi, cloud etc

IMHO, TeslaFi is more feature rich, but TeslaMate is probably easier on the eye and because its self hosted, is more customisable.

TeslaFi gets the odd question once in a while. There is a 56 page thread on TeslaMate here TeslaMate [megathread]
 
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I’ve lost 3% overnight while the car is not plugged in. Is this usual?
Was some of the ‘loss’ due to a cold battery? In cold weather conditions the BMS will retain a small portion of the stored energy, usually 1-2%. This occurrs when a blue snowflake is visible on the in car and app, battery display. Was some of your reported loss, merely the battery taking care of itself? The retained energy is returned when the battery becomes warmer.
 
Another 24hrs another 4-5% battery loss thanks to the crappy “fire” software update. Are they just doing this so there is something worse than the awful UI bodge?

I really couldn’t care less about the cost, running a Tesla is peanuts. Simply this is not the green future I was looking for.
 
Mine loses 1% in around 5 days parked up with no API stuff going on and no checking on the app - in 10-20 degrees C

Since the weather got a lot colder / continually at less than 10 degrees, it loses about 2% in a week.

However I’m not convinced it’s losing even as much as that, I think it’s the BMS making capacity unavailable, as once I’ve driven for around 10-20 miles, I seem to have a period where the % usage calms right down and gives me more “miles per %” than would be normal.

Ergo, it all evens out and seems to stay highly efficient - despite the lower temps. I reckon mine loses 20-30% efficiency in the cooler months.

Overall LR average 308wh/mile since early Sep over 3500 ish miles from new. Around 800 of those miles in cooler temps.

I have deliberately avoided any thinking or analysis on Miles Range since I got the car as when researching the car before delivery it seemed that therein madness lies. Have just gone with it and tbh have barely used the energy graph and have driven it on % display since mile 1.
 
driven it on % display since mile 1.

Same here, since 02 June 2018...avoids much "minutia grief".

barely used the energy graph

Again, same here.

Way back in version 8 (prior to Q4, 2018), the estimated %SOC icon at nav system destination was always displayed right next to the active ETA.

When V9 came along, that icon became hidden in the display of all the turn by turn instructions whilst the (IMO) useless energy graph page was introduced.

My technique when driving a long leg where energy consumption is critical: pull up the map view that shows the whole route (in the nav system) and scroll up the turn by turn instructions until I see the estimated %SOC icon at nav system destination and leave that displayed...if the %SOC (number at destination) starts to shrink, slow down...if the %SOC (number at destination) starts to climb, speed up...
 
I've installed TeslaMate to monitor the phantom drain. I have lost 6% of SoC in 3.5 days. I've tried to align the states dashboard with the Vampire drain dashboard (unfortunately there is no dashboard that combines the two?).
What you can see is that the car is sleeping for most of the day but then wakes up for 3-5 hours at a time and these periods are directly linked to drops in the SoC (as you would expect I guess) but at least it shows the correlation and that the drop in charge is not gradual but caused by long periods of being awake and doing nothing. Btw. Sentry mode is switched off.

Screenshot 2021-01-22 at 08.39.34.png
 
Mine is now doing the same, and my Teslamate plot looks very similar to the one above. The car is now staying powered on for much longer when it makes its daily "phone home" call. No idea why, as it used to only stay awake for around 10 to 15 minutes when it did this, now it's staying awake for an hour or two each time, significantly increasing the battery drain when parked up and not being used much.

This is a recent change, since the last two software updates (for some reason my car did both on the same day, about a couple of weeks or so ago).
 
Until the last update (48.30) mine woke every night for 31 minutes, always within the octopus go cheap rate period. Since update 48.30 it has woken consistently each night for 1 hour 36 minutes except for today (friday) where it returned to waking for 31 minutes.
I'm using teslafi to monitor activity and the car charging timer to schedule charging however I've not charged since last weekend and the BMS is reporting ive lost 1% since then.
So different again from other owner experiences.
 
I've been having this problem since 48.30. I thought it might be temperature related , but I'd have expected more variation in the sleeping patterns as the temperature got warmer. I've had a reasonable period of long sleeps, but it looks like it's going back to the online/asleep cycles again today. On the graph below (quite easy to set up on Teslamate - ping me if you need a hand) you can see the cycles started just after 31/12 which is when I installed 48.30. I would be good to compare this to another car in a warmer climate to rule out temperature as a factor.
Screenshot 2021-01-22 at 11.14.06.png
 
Mine is in with the service centre at the moment and this is one issue I raised. Before I went in (after a load of "can you tell us the times and dates this is happening" questions I spoke to a person and they could see the car awake and mentioned something with the 12v, so I will see what they come back with when I pick it up. They were pretty reluctant to se it as a problem at first, I assume they hope a software fix will fix it and must spend a lot of their time fed up about these type of bugs.

I can only recommend everyone requesting a service visit to fix and generating sufficient workload to force them to deal with issue at HQ.