Where did you install the winch? BTW are you in socal?I've had great success with the BEP:
I have a 2003 2520XL with single outboard and have installed the BEP cluster switch. I primarily tuna fish, and spend most of the time on the hook running livewell pump, fish finder, radios, etc.. on house battery. I was always running out of power, but since switching to BEP I have had zero battery issues. When I installed the BEP I also installed an extra house battery based on my usage. Here is my configuration:
I have a group 25 starting battery that is wired to the BEP start switch
I kept the original battery switch (1,2,both,off) and wired the output to the BEP house switch
I have 2 group 31 deep cycle batteries connected to the original battery switch
I have a guest 2 channel battery charger that is wired to the house batteries so that they are charged individually when on shore power
Using the standard battery switch I select either battery 1, or battery 2 such that only one of them is connected to the BEP house circuit.
By doing this I always have a full deep cycle battery available to me when offshore. FYI - I have never had the need to set them to both.
When running, the BEP always isolates the house from spikes during startup, and then charges the starting battery to full before switching the relay so that both the starting, and the selected house receive charging from the running motor. When on the hook, the relay switches as soon as the level drops, protecting my starting battery, and running on the one selected house battery. If this runs down, I can simply switch the original battery switch to the other battery.
No regrets here, the install was clean, works perfectly, and everything is in the bilge.