My cranking battery would turnover engine after running the anchor light for about 30 minutes. It started the engine fine the three times prior to running the light, the engine was also ran for atleast 10 minutes after each start.

When I got home I put plugged in the onboard charger. After charging for about 12 hours, I unplugged the charger and checked the voltage. The trolling battery had around 13.4, while the cranking had about 12.6

I proceeded to do a few tests scenarios:
Turned on Running lights only (anchor light unplugged) battery voltage 12.4
12.3 volts at 11:34
12.24 volts at 12:39
Cutoff running lights at 12:40 voltage 12.45 at 12:45

Turn on anchor light only, voltage 12.32 at 12:46
12.27 volts at 1:06
11.23 volts at 3:36

Cut lights off , tried to crank. Turned over very slow but wouldn't start. Voltage at 10.4 after attempt.

I'm guessing I can run it to an autozone type store and have it checked? Thanks in advance for any advice.