homer
Well-Known Member
Since battery to battery chargers are expensive, I use a variation of option 2. I simply have a 2.5 mm2 wire running from the house batteries (aft) to the bow thruster battery (forward). As per my calculations, ther is too much resistance in this cable to draw much current through it when the bow thruster is in use but it allows a moderate charging current the rest of the time. It also means that the house batteries draw upon the bow thruster battery, in effect, increasing their capacity. The only potential downside is that if the house batteries were run right down so would be the bow thruster battery (but I don't let that happen). The connecting wire is, of course, fused (10 A). Please don't tell me this system wouldn't work as it has done without any problems for 2 years (and that is 2 years liveaboard).
