Niro EV battery drained after left for a week

[bmxrider]

I was on a business trip and when I returned, I couldn't open my doors using the remote key fob and had to open it manually. The vehicle wouldn't start as well. I had to jumpstart it, despite the fact that the battery was nearly full. I believe the rear door was left open, which may have caused the problem. Why did my 12V battery die? Shouldn't the HV battery charge it automatically?

 

[Sfumato]

I've been having some issues with my hybrid's 12V battery.
It seems like the HV charge count resets every time I turn the car on, and it's only charging a few times before going dead.

Before a long trip, make sure everything is locked up tight and all the scheduling is off, or you'll come back to a dead battery. I learned this the hard way after leaving the trunk open overnight and the battery died in just a few hours. It's also been causing the battery to degrade slowly.

The only long-term solution is to upgrade to a lithium 12V battery, which is what Tesla does. They even use 16V lithium batteries now.

 

[Lbutera036]

This is a good reminder that these things can be unpredictable. I agree with @Sfumato to upgrade the battery. I've read a lot about leaving a door open and causing issues with the battery.

 

[CamiNiro]

Leaving the trunk open can quickly drain the 12V battery because some systems, like lights, sensors, or alarms, may stay on and keep drawing power. Even though hybrids are designed to be energy-efficient, an open door or trunk can prevent the car from entering its low-power state, leading to faster battery depletion.