Keep Hotspot active after shutoff.

[1454]

This is a convoluted question, but I would like to add an inline battery to the hotspot/onstar unit, or add a shutdown timer. I only need about 6-8 hours. I'm looking to accomplish this due to adding an wifi incab temp monitor for leaving the furry one in the truck for short periods. Then crank as needed to cool or warm the truck. 

 

If anyone has any other suggestions, I'm all ears. I know they make an rv units, but I prefer non proprietary temp sensors. And they ask a laughable 30/month and it seems to not even do instantaneous monitoring. (I think like 30sec to 1 min updates) 

 

Please no lectures about not leaving animals in a car. I'm asking to do what I am doing so I can do so safely for her. 

Edited December 31, 2022 by 1454