sparkfun ZOE-M8Q Manual page 12

Power
Power for this board is 3.3V. There is a 3.3V pin on the PTH header along the side of the board, but you can also
provide power through the Qwiic connector.
Battery
The small metal disk in the upper left corner is a small lithium battery. This battery does not provide power to the
IC like the 3.3V system does, but to relevant systems inside the IC that allow for a quick reconnection to satellites.
The time to first fix will about ~29 seconds, but after it has a lock, that battery will allow for a one second time to
first fix. This is known as a hot start and lasts for four hours after the board is powered down. The battery provides
over a years worth of power to the backup system and charges slowly when the board is powered.
LEDs
There's a single red power LED just above the Qwiic connector to indicate that the board is powered. There is
another LED labeled that is connected to the Pulse Per Second line on the GPS chip. When connected to a
PPS
satellite, this line generates a pulse that is synchronized with a GPS or UTC time grid. By default, you'll see one
pulse a second.