Welcome back to evfixes.com. Today we are going to talk about something that really bothers a lot of electric vehicle owners. You know when you wake up and your cars battery is not as full as it was when you parked it. This is called Drain or Phantom Drain.
If you notice your vehicles range goes down overnight that is really frustrating. Your car is turned off. Some things are still using power in the background. We will look at why this happening to your electric vehicle and what you can do to fix the problem with your electric vehicle.
What Causes EV Vampire Drain? (Top Reasons)
Before we try to fix the problem we need to know what is causing the energy loss in the place.
The things that use up energy in our cars are important to understand.
- Sentry Mode and Security Cameras
Cars like Tesla have security cameras that’re always on. Sentry Mode helps keep our car safe by recording what is happening around it.. It also keeps the cars computer on all the time which uses a lot of energy.
- Battery Thermal Management
The batteries in vehicles do not like very hot or very cold temperatures. So when it is freezing or very hot outside the cars computer turns on heaters or coolers to keep the battery safe. This helps the battery longer but it also uses up some of the battery power.
- Mobile App Polling
We often check our cars status using an app.. Every time we open the app the car has to wake up and send us the information we want. This means the car cannot go into a power-saving mode.
- Third-Party Apps
Some apps that track our cars statistics or trip logs are always asking the car for information. This keeps the cars systems turned on all the time, which uses up energy.
- Onboard Electronics
Things like dash cams or OBD-II scanners that are plugged into the cars power outlet can still use energy when the car is turned off. This is something we should be aware of when we’re trying to save energy in our cars, especially our electric vehicles, like Tesla.
How to Stop EV Battery Drain: Practical Solutions
To help you save range, here is a quick summary table of features and the actions you should take:
| Feature | Recommended Action |
| Sentry Mode | Use “Exclude Home” setting to turn it off in your secure garage. |
| Climate Control | Turn off “Keep Climate On” and “Cabin Overheat Protection” at night. |
| Mobile App | Avoid refreshing the app unnecessarily; force-close the app after use. |
| Software Updates | Always install the latest updates; they often include efficiency fixes. |
| Parking | If possible, park in a garage to shield the car from extreme weather. |
Pro Tip: A drain of one to three percent, over twenty-four hours is usually okay.. If you lose five percent or more something might be going on in the background. In that case try restarting the cars system or resetting it softly.
Special Guide: Tesla vs. Mercedes-Benz
Different brands handle standby modes in their way. Here is how to optimize the two popular luxury electric vehicles.
For Tesla Owners
Teslas are like computers on wheels. This means they use power when they are on standby.
- Fix Sentry Mode: Go to your security settings and turn on Exclude Home.
This will help reduce power drain.
- Dog and Camp Mode: Make sure you turn these off after your trip. They can use a lot of power if left on.
- Cabin Overheat Protection: Change this to No AC mode. It uses the fan to cool the car. This saves a lot of energy compared to using the compressor.
For Mercedes-Benz Owners (EQS, EQE, EQC)
Mercedes-Benz cars have a deep sleep feature.. You can still lose range if you are not careful.
- Mercedes Me Connect App: If you park in an area with no network your car will keep trying to find a signal. This can drain the battery fast.
- Pre-Entry Climate Control: Check your Departure Time settings in the app. If you have a schedule set your car will. Cool the cabin before you get in. This uses battery power.
- Key Fob Proximity: Keep your fob away from your car. If it is, within 15-20 feet the sensors will stay active.
This expects you to get in the car.
- Standby Mode: If you are going on vacation use the Standby Mode in your settings. This turns off all -essential sensors.
Does leaving an electric car charging overnight cause the battery to degrade faster?
Depends on what SOC you charge to. For longest life, you want to aim for a medium low average SOC.
An example; you leave home at 70%, return that night at 30%. Average SOC was approx 50%. You plug in, timer set to start during lowest rate period, you have 70% the next morning and so on.
This is how most “should” be doing it on a daily basis. Nearly all of us pretty much know how much driving we will be doing so its quite easy to manage the SOC.
Have an unexpected detour? Meeting wifie for dinner out, etc? Well, you got 30% which in a 200 mile range EV is somewhere around 60 miles. Lets face it, you will RARELY need that much.
Granted, on weekends its much less predictable for some.
As far as me? I run 30–50% during the week and then up to 75% SOC on weekends. Realize a low SOC is not bad for the battery. You just want to make sure its not crazy low because that will cause immediate permanent damage.
Time at high SOC is bad EVERY second but its like death by a million tiny cuts. It will take months or years before you notice anything and by then? You really have no clue how it happened.
So charging every night? Its a must. I pay $225 a year for EV tabs in my state so have to save anywhere I can.
Just kidding!!
The price of gas here ranks in the top 3–4 in the nation. I save THOUSANDS every year driving EV. 😉
Can you leave an electric car charging overnight? Is it bad to leave your electric car plugged in?
When it starts and stops charging has nothing to do with being plugged in.
The charging will stop anyway. You can set the time to start charging and the SOC (State of Charge in percentage) to stop charging.
It is best to only charge to full when you need it and also occasionally for better battery cell balancing. But it is best to charge when above 20% SOC and stop the charge before 80% SOC. But do not hesitate to charge to 100% when you think that type of range is needed, around 300 miles at 65 MPH on my Tesla Model 3, AWD, LR. I only rarely need such range.
If on a long vacation, away from the EV, keep it plugged in to stop the charge at around 70% SOC. When it drops to 69% it will charge back to 70%, which will happen every few days. Charger will turn on for just a few minutes and shut off automatically.
Charging more often is faster than less often for the same distance. Charge more in the lower mid range as that is where the charging is fastest. The charge rate must slow down a lot near the top 15% SOC.
EVs are much more advanced than you seem to think. For an example, I own a couple of houses 100 miles away in two different states. They each have a lower electric rate at night for EV owners but at different times. I set the start time one time at each location and the car remembers the time to start the charge for each. It uses the GPS for everything possible. Things like above that most people would never even think about.
Any new location will be instant charging, until a start time is set.
And it doesn’t end there. Put your mirrors in one time to get into a very tight spot. Next time they will go in automatically just before you get there. You can also do the same with your garage door opener. It just opens your garage when you arrive, you press no buttons. And if you don’t like these features (for whatever reason) there are ways to turn them off.