12 volt outlet in frunk

[John Rogers]

I installed a fused 12 volt socket in my Model 3's frunk directly off the car's 12 volt battery to run a small car fridge. Can anyone tell me if the 12 volt battery will charge off the traction battery when the car is not running? The fridge draws 30 watts.

 

[SageBrush]

I'm not an expert. I'm under the impression that while the car is parked it polls the 12v voltage periodically and tops it up according to pre-set thresholds. My guess is that your setup will work, although the 12v drain will be inefficient to replace because the car will wake up for the task, and the frequent cycling of the 12v will lead to early replacement if the car fridge is operated often.

 

[webbah]

The only risk might be that the car will interpret the voltage drop as an error with the 12v battery and need replacement as the Tesla firmware is unaware and not configured for outside of scope drain. I also have this potential issue and went with an Ohmmu Lithium battery instead as it maintains higher rates of charge for longer periods vs lead acid OEM. I'm drawing roughly 10w continuous for Blackvue DR900S dual channel cameras and a Teltonika RUT850 Automotive Wifi/LTE router. I have not had any errors in 15 months in my case. Kill switches installed in the driver footwell to disable both when/if I want to. Also installed a bluetooth 12v battery monitor that sends push notifications to my phone and with the app I can see historical drain rates during idle, sleep and driving patterns.

I should note that I tapped directly into the 12v continuous wiring harness of the car instead of directly to the 12v battery for this reason as well. The car will "see" the usage.

 

[John Rogers]

Thank-you SageBrush and webbah. My use while the car is not in use is only very occasional so should not lead to too much drain. Time will tell.

 

[Rockster]

I have heard stories from those who have installed always-on dash cams that the Model 3 detects the draw against the 12v battery while the car is off and eventually throws a fault.