Battery won't charge. Help!

[KettererUSA1]

Hello, I have a cabin that I have set up with the following gear:

Sunforce 60031 10 AMP Digital Charge Controller
Aleko 20W polycrystalline solar panel (12v)
Deep cycle marine battery (575 cca)

I have this system in, but the battery never fully charges. As a matter of fact this morning when I went to check in it, the battery read 13.61v. Now, the end of the day (sunny all day) it reads 13.01v. The system has not been used all day. What gives? I replaced the charge controller once already. Not sure what is going on.

Any ideas?

Thanks.

[Sunking]

Deep cycle marine battery (575 cca)

For one that is not a deep cycle battery. Deep Cycle batteries do not have Cold Cranking Amp. Only batteries that specify CCA is Starting Batteries aka Cranking Batteries. Deep Cycle only specifies Amp Hours and only Amp Hours. Cranking batteries should not be cycled or they fail very quickly.

But to answer your question I have no idea what the AMP Hour rating is but let it rest disconnected a few hours or over night and measure the voltage. 100% = 12.6 to 12.7 volts on a rested battery. Sounds to me the battery is fully charged up and the CC is in float mode meaning it is not charging and will read 13.6 volts in FLOAT mode.