Investigating Unexpected Battery Drain While Idling - Consider Factors Such as Charge Level, Location & More

It is surprising to find that a 4-day old BMW iX50 battery drops at least 5% every night while sitting outside in Maryland. This is similar to the Tesla vampire drain levels before 2018, when they had not yet sorted out their software tuning. Generally, one would expect 0% drain for days at a time, as has been observed with a car left in a parking garage for a week and charged to 80%. To investigate this issue further, it is important to consider the charge level before the 5% declines, whether the car is sitting in direct sun, if it is making any noise, and if rebooting the car helps.

For instance, one user left their car at the airport for almost 3 weeks at 92%, and returned to 92%, with no decrease in battery % while parked overnight. Another user went away for a week with their car left in front of their parents’ house (in summertime temps) and did not lose a percent. It may be helpful to set up daily preconditioning before leaving the car, as this can cause cooling/heating every day at the preset time (also on battery), which can consume 4-5 kWh.

It is also important to check if unlock on approach setup is enabled for keys/digital key, and if the location of the car is within range of where you have the key/phone. Additionally, make sure that your car is turning off after exiting by setting up the option to turn off when exiting. After walking away from the car, go back out to the car an hour or two afterwards to see if your screens are still active and alive.

In conclusion, it is important to investigate further when observing unexpected battery drain while idling. Consider factors such as charge level before decline, location of the car, noise made by the car, and settings related to unlocking and turning off after exiting. With these considerations in mind, it should be possible to identify what is causing the unexpected drop in charge while idling.