12v trunk port staying on?

[SSGP90X]

Hi,

I have a 2020 long range x, had a question about the behavior of the 12v trunk port and it staying on longer than I expected. My prior understanding had been that it stays on while the car is on, then shuts off after a few minutes. Exceptions to this are camp mode, where the main battery will power it (as opposed to the 12v battery).

I have a dometic fridge and a jackery 500 portable battery that I purchased for a road trip, with the idea of the jackery powering the fridge overnight and with the car recharging the jackery during day driving. My setup Is the dometic fridge connecting to the jackery, which connects to the 12V trunk port.

Today I noticed that the next morning after recharging my Tesla that they jackery still read at 100% battery (ie, the car had kept the jackery recharged despite being off overnight and not in camp mode). How is this possible? Is there any way to figure out if my 12v battery is being used to recharge my hackers (ie, is Susceptible to dying if I didn’t turn my car on for a few days) or where it’s my main battery doing this?

thanks

 

[superdry]

If it's the case that the trunk 12V stays on always, that's great news as far as I'm concerned (perhaps with a cutoff if the battery goes below 20%). Some people would want it to stay on all the time, such as people that want to have a refrigerator without having to get an external battery unit like you did. Those that want to be able to have the car sit for days and not have the battery wear down have the option of unplugging their accessory.

 

[SSGP90X]

If it's the case that the trunk 12V stays on always, that's great news as far as I'm concerned (perhaps with a cutoff if the battery goes below 20%). Some people would want it to stay on all the time, such as people that want to have a refrigerator without having to get an external battery unit like you did. Those that want to be able to have the car sit for days and not have the battery wear down have the option of unplugging their accessory.

is there any way to figure out if the power is being drawn from my main battery pack or the 12v battery?

 

[scottf200]

Today I noticed that the next morning after recharging my Tesla that they jackery still read at 100% battery (ie, the car had kept the jackery recharged despite being off overnight and not in camp mode). How is this possible? Is there any way to figure out if my 12v battery is being used to recharge my hackers (ie, is Susceptible to dying if I didn’t turn my car on for a few days) or where it’s my main battery doing this?

The truck 12v socket use to stay on if sentry was on as a by product. This worked great for my fridge. Then it stopped with some OTA, AFAIK. Maybe it is working again.
It was annoying to me and as well that I would have to remember to turn on camp mode. I ended up wiring it to the electric trailer brake 4 pin in the footwell. I have post about this.

You are confused about the main HV battery vs the 12v battery. Always comes from the 12v battery. The car monitors the 12v battery and if it gets low then the DC to DC converter charges up the 12v again. Quite a few threads/post on this.

 

[SSGP90X]

The truck 12v socket use to stay on if sentry was on as a by product. This worked great for my fridge. Then it stopped with some OTA, AFAIK. Maybe it is working again.
It was annoying to me and as well that I would have to remember to turn on camp mode. I ended up wiring it to the electric trailer brake 4 pin in the footwell. I have post about this.

You are confused about the main HV battery vs the 12v battery. Always comes from the 12v battery. The car monitors the 12v battery and if it gets low then the DC to DC converter charges up the 12v again. Quite a few threads/post on this.

thanks. I read a few of them but was confused. So then is it basically impossible for me to ‘kill’ my 12V battery by having the dometic fridge run for too long? Using the fridge function, the jackery 500 battery alone can keep the fridge powered for around 40 hours which is great. However on this trip we decided to use the dometic as a freezer and the power consumption I realized is significantly higher, jackery 500 would likely only last 12 hours. I was concerning with it killing my 12V

 

[scottf200]

thanks. I read a few of them but was confused. So then is it basically impossible for me to ‘kill’ my 12V battery by having the dometic fridge run for too long? Using the fridge function, the jackery 500 battery alone can keep the fridge powered for around 40 hours which is great. However on this trip we decided to use the dometic as a freezer and the power consumption I realized is significantly higher, jackery 500 would likely only last 12 hours. I was concerning with it killing my 12V

The Dometic fridges are pretty efficient.

I've used my Dometic CFX-35US fridge (in my '17 X on a few long roadtrips and ran it constantly often at like 33F. I surprisingly haven't had to replace the 12v battery yet as 'normal' users often need it replaced every couple years. I'm going to test mine when my new tester arrives (Wed?) -- P100D X 12V battery dying in a car without any warning?

Originally when I first put in my BlackVue dashcam, I put a separate battery in for that so it would run with the 12v rail was down. On a weekend trip, I saw my battery was completely full after. Turns out it was Sentry that as a by-product kept the 12v rail active. As that has turned out unreliable AFAIK after differ OTA and my fridge not working, that is when I 'hardwired' it.

I read many threads/post at the time and various people saw that the 12v battery was being monitored and being maintained by the HV battery system. ie. your 12v battery won't be drained ('killed' to use your word). You can always buy something like this if it makes you feel better to watch your 12v's voltage to give you some mental relief. https://smile.amazon.com/Battery-Charging-Condition-Alternator-Display/dp/B07422ZPT4