What kind of battery does the mini car refrigerator 12v use

mini car fridge 12v should never run off the cranking battery that you use to start your vehicle. The only exception to this is while you are driving if you absolutely must. The reason behind this is simple – your cranking battery is imperative to start your vehicle, and if you run it flat you can be in serious trouble.
The most common way to run a fridge is with a second battery, which is isolated from the main cranking battery. The best option is a deep-cycle battery, which is designed (as the name suggests) to cycle from full to half empty and back again, anywhere from 1200 – 1700 times.
You can run them off a normal cranking battery, but they don’t like to be cycled and you will shorten its life substantially. Lithium batteries are also becoming more popular as they have several advantages, but they come at a pretty hefty cost.
Dual battery system under car refrigerator with compressor hood
Do not run your fridge off your main battery. Run a dual battery setup.