Some like a forward battery, but....
the common opinion is that you are better served with your larger existing house batteries. The discussion is as follows:The house bank is much larger than the battery that you would install in the bow. These windlasses draw 150-250 amps under load. A small (group 27 or 31 battery) may not provide the power you need for difficult situations. For example, suppose you anchor and find that either you are not set or are too close to something and you have to pull up and re-anchor. What if you need to do this action several times? You may not have enough reserve in the bow battery to do this.A battery mounted in the bow has the disadvantages of weight where you don't want it, and it is subject to much more violent pounding underway than the existing batteries further aft. I question whether that is good for the life of the battery.The charging wires to this bow battery need to be quite substantial if you are going to use your engine alternator, generator, or existing battery charger. If you decide to put in a dedicated battery charger, then you must have a generator so that when you are cruising and going from anchorage to anchorage without dockside power you are able to recharge the dedicated battery.The only downside of using the existing house bank is that you need to run a pair of 2-0 cables from the batteries to the bow. The cables will cost about $325 plus you labor to install (see Jamestown Distributors for a great price on battery cable).In addition to the performance conserns a bow battery will also cost $80, a dedicated marine charger $150, 120V cable for the charger $25, and control cable for the reversing solenoid $15. Plus you may be giving up storage space, and you now have an additional battery to maintain.Check in the archives for this topic. It has been discussed before now. Other ideas may help you decide.