There are two battery banks on my boat - House and Starter with isolator switches.
The solar input and aux alternator connect to the House bank, so i wanted to take the benefit of the solar and trickle charge the Starter battery.
I have the Orion TR Smart 12/12-18a Isolated dc-dc charger in between the two battery banks
Inputs - Positive from House bank / Negative from House bank
Outputs -Positive to Starter battery / Negaitve to Stater battery.
(fuses between batteries and Orion)
The jumper cable is left in as there is no remote, or on off scenario. The settings compensate for this by setting the minimum voltage that i want to start charging (so if the solar input pushes the House bank voltage past 13v the Orion starts charging the Starter battery)
The Orion is charging the Starter battery only when the the volts are high enough, so working perfectly.
However the problem is overnight, when there is no solar, and we are drawing loads from the house bank, the volts drop on the house bank (naturally), but the Starter battery is also being depleted.
I don't understand why the Starter battrry gets depleted -surely there would be a diode in the Orion to prevent draw from the target battery? Is there a setting I am missing or does the wiring need to change?