"Peter Bennett" wrote:

Although the bow thruster and anchor windlass need significant
currents when they are used, they are normally used for such short
times that the actual energy (amp-hours) used from the batteries is
almost insignificant.

My anchor windlass (31 ft power boat) is fused at 80 amps - say it
draws 60 amps when raising the anchor. It will typically run 2 - 3
minutes to raise the anchor - at 60 amps, this is 120 - 180
amp-minutes, or only 2 - 3 amp-hours. The bow thruster may draw 200
amps, but is only run for a few seconds at a time - normally well
under a minute when docking or un-docking, so that again is only a
couple of amp-hours - hardly worth worrying about when considering
your daily power useage.
-------------------------------------------------------------
You have lemons, make lemonade.

Locate your dedicated windlass battery in the bow as close as possible
so the large load cables will be relatively short.

Disconnect the windlass battery from ALL other electrical devices on
the boat so that it is isolated.

Fit the windlass with a dedicated 10W solar panel complete with
regulator.

You will maintain a floating charge on the windlass battery except at
night.

The same concept can also be applied to the starting battery.

Throw a pair of jumper cables in a locker for use under emergency
conditions such as total windlass or starter battery failure.

Have fun.

Lew