Battery not a good idea
I appreciate the feedback from everyone. I think I'm going go with Steve's suggestion and install a battery at the bow and and hook it up to a solar charger I salvaged from my old '69 Bristol 24. I'll let you know how it turns out. - Thanks again.
Most often, they use a separate battery for a thruster, but not for windlass.
Here are the drawbacks:
You need to charge this battery. Usually people use an echo charger, which is limited to 15 Amps.
If you're anchored with maximim rode out, you'll be surprised how easilly you can flatten a battery which is 1 or 2 seasons old.
Speaking for myself, I've gone into anchorage, Where I've had to set & reset several times. Now imagine doing this at night with your battery winding down.
People use external batteries for thrusters as they assume the duty cycle is low, and if the battery dies, its not tragic.
How are you going to get your anchor up if the battery flattens.
The correct install is from the house bank.
You will have the engine running while anchoring, which will be recharging at min 80 amps; not 15 as per echo charge. You also have the full capacity of your house bank to use.