How do I insert a Lithium battery into a Brass Monkey fridge? How do I store the battery?

Have a look at this video for how to install the battery into Brass Monkey fridges that support an optional internal lithium battery: https://bmc.worldmanager.com/go/MKW4qR

When not in use, please charge the battery up until at least 3 of the 4 LEDs are lit, remove the battery from the fridge, and turn it off (hold the button down till the lights go out).

You should check it every few months by turning it on, and recharge it if the LEDs are indicating it has self-discharged.