Something needs to be a known. We either need a battery of known quality, a windless motor that we know is good or circuit that has been tested and gone through where every component is known to be good. It doesn't sound like we have any of these so working to a conclusion is going to be hard. Secondly, a charge rate of 16.2 is way the hell to high. We should be in the neighborhood of 14.0 to 14.8 for flooded, 13.8 to 14.6 for Gel. and 14.0 to 14.6 for AGM batteries. Even in an equalize mode the maximum output voltage shouldn't be above 16 volts. What I'm afraid has happened is that your charging the windless battery too high which has resulted in it being overcharged, heated and rendered bad. When you first try to recover the anchor the battery has enough power to work for a while but then starts to die. The No. 8 wire isn't large enough to carry the windless load so the windless motor voltage drops, the amps go up and the circuit breaker trips. From the battery to the windless motor, the circuits and components are the same as any other installation. You have the foot switch which picks up the contactor that connects the battery to the motor and all the connections in between. All these components still need to be checked for current and voltage carrying capacity. The difference in your system from most is that the battery is located at the windless instead of 30 feet away. It's great if you don't want to run larger wires to the bow from your house bank. The downside is that you have another battery to deal with and if that battery goes south, you can't haul up your anchor using the engine and house batteries. The smaller charge wires can't (usually) pass enough current needed to run a windless. If you are charging the anchor windless battery at 16.2 volts and your charge wires are connected directly to your alternator then you are charging your house batteries at the same 16.2 volts. Check your house voltage at the batteries while running your engine after you have let them discharge for a few hours with some lights on. Get the house battery voltage down enough so your regulator will be forced to provide a full charge when you start the engine. Check the house battery voltage and then check the charge voltage to the windless battery. They should be about the same. Both batteries should be within the range listed above. If it is a flooded windless battery get a hygrometer at your local auto parts store and test the water. That should help determine the condition of the battery and help us find something constant to start to work from. Good luck.