Diode fitted on Bow Thruster Charging Circuit

The bow thruster batteries now share charging from the 55amp alternator with the starter battery. There is a relay between the starter battery and the bow thruster batteries. I understand that there is a risk that the bow thruster will try to take power from the starter battery. As the rating of the relay is significantly less than the bow thruster this could cause the really to fail and cause a fire.

To prevent this a split charge diode can be used to replace the relay. This is what I planned to do. I was concerned as space there is limited. Also the diode needs to disperse heat and this would be impaired in the engine space. My solution has been to fit the diode at the bow thruster end of the charging circuit in the front locker with the batteries.

Taking voltages, there is a loss of 0.74v from the cable run from the engine space to the diode and a further loss of 0.79v across the diode, so a total loss of 1.5v.

Further battery update

After much frustration fitted the 70 amp alternator warning light. I put the cable through when first fitting the second alternator. The fustration was first trying to get it to work when there was a 'gap'  in the cable (intended but forgotten about!) then when there was no bulb in the new warning light.

Connected the shore battery charger to the bow thruster battery circuit. Unfortunately not neat but safe and out of sight.

Fitted the Sterling Advanced Regulator but no evidence from the SmartGauge of any effect. I'll investigate further when cruising after a night away using the domestic batteries.

Final outstanding task is to fit the Sterling Split Charge Diode, when it's received.