Power Source Options:
There are multiple ways to power your 12v compressor fridge. You can run it off an AC/DC adapter while on 120v power, you can run them directly off a 12/24 volt portable battery pack, or you can run them off your vehicle/boat 12v socket. I will discuss each one below:

AC/DC Adapter:  Running your 12v fridge off 120v power is very simple. If your fridge comes with an AC/DC adapter it allows you to use the fridge while at home for extra refrigeration space or in a hotel while on a road trip. Not all fridges come with AC/DC adapters so you might have to purchase one separately. If you are planning to head out on a road trip you can use your AC/DC adapter to pre-cool your fridge before leaving. Just plug in your fridge a couple hours before loading it up, set the desired temperature, and you’ll be good to go when it’s time to load up the food.

Portable Battery:  After years of experience the best way to power a 12v fridge is to use a portable battery setup. Many of these portable battery setups accept multiple charging options from solar panels or other DC power sources. These portable batteries are called solar generators and they are getting more affordable each day. You might recognize big brand names like Goal Zero, Jackery, and Bluetti. Each brand offers different sizes starting around 150wh all the way up to 1500wh. With a 500wh battery pack you can expect over 24 hours of runtime on a 12v fridge during a warm afternoon. I would not recommend anything under 500wh to power a fridge. With the addition of solar panels or DC to DC charging you can charge the portable battery and run a 12v fridge forever. You can also make your own battery packs using LiFePO4 or lead acid batteries. Check out my YouTube build videos if you are interested in building your own battery pack for more value for your dollar spent.

12v Vehicle Socket:  Using your vehicle starter battery to power your fridge is only recommended while driving or only for short periods while the engine is not running. If you plan to run your fridge off your vehicle 12v system you’ll need to monitor it very closely. I have used my 4Runner starter battery to run my fridges but one can easily run the battery down too low, cause permanent damage, and leave yourself stranded with a dead battery. Most vehicles weren’t designed for 12v fridges in mind and their power sockets shutoff without the key installed. Some vehicles also have smaller wire which causes large voltage drop so your fridge won’t even power on.  So unless you plan to modify your vehicle wiring or run a second AGM/LiFePO4 vehicle battery it’s best to stay away from this option.