Posted: Thu Jan 17, 2013 1:47pm

Hi There, I spend most of my time connected to shore power as I live on my boat; would you advise if it is beeter practise to have the shore power selected to charge the battries only and have the inverter supply the 240 requirements or to have the shore power selected to supplying the boat 240 and charging the batteries? Thank you, Shaun

Posted: Thu Jan 17, 2013 4:39pm

The answer depends upon exactly what equipment you have and maybe the circuit breaker setting on the shore supply "pole". If this is a relatively modern combi-inverter then it will probably sort it all out for you once you have set it to what the shore supply can deliver by turning the inverter function on under high 240ac loads to "top up" the shore supply. If you have one of these just make sure that you set it so the inverter function is turned OFF but the battery charging function is ON when you leave the boat for longer periods. If you have a less sophisticated combi-unit or a separate inverter and charger then what you do will be dictated by the shore supply. If the boat mains equipment wants more electricity than the shore line can supply you will have to use the inverter otherwise do what you like but I would seek to minimise the discharge-charge cycles of the battery bank. The more you cycle them the shorter the lift. This then brings us to the output of the charger. If the charger can supply more amps than the inverter demand then its the charger that will supply the inverter, not the batteries. If the output is lower than the demand then both the charger and the battery will supply the inverter. The only "better practise" thing here is to try to minimise the battery cycling and without detailed specifications for your boat's equipment and shore line post's circuit breaker setting I can not say much more. Tony Brooks

Posted: Sat Jan 26, 2013 9:52am

Thank you for your response Tony; my boat has a combined inverter/charger and the shore supply is 16 amp so I shall continue to use the shore supply as the primary source with the inverter providing the top up as required. Thank you for the note about selecting 'charger only' when leaving the boat unattended. Many thanks, Shaun