I do NOT recommend using the battery unless if you can make sure it has regulated output voltage at 12V or below.
You can use a 7805 linear regulator, a switching regulator like this:
https://www.amazon.com/DZS-Elec-Adjustable-Electronic-Stabilizer/dp/B06XRN7NFQ
or a simpler solution is to use a bunch of diodes in series as a way to drop some voltages. Please make sure that the input voltage MUST be provided through the black power barrel, NEVER provide input voltage through the pin named VIN — the VIN pin is a 5V output pin for powering certain sensors, it’s not for input power.