What type of battery terminal is this?
Anderson Powerpole

Powerpole connectors are available with current ratings up to 180
amperes. The size most commonly used is the 15/30/45 ampere-rated
variety. These sizes all use the same plastic housing in multiple
colors, differing only in the metal contact inserted into the housing
(selected based on the ampacity and wire size). The colors can be
used to signify signal types (power, speaker, logic, microphone audio,
etc.) or differing voltages. Powerpole connectors can be attached side
to side and also stacked on top of each other to make, for example,
four connections with one plug insertion.