Solar Relay for AC backup

Discussion in 'General Electronics Chat' started by jm317, Jul 11, 2009.

  1. jm317

    Thread Starter New Member

    Jul 11, 2009

    I have a small solar array linked to 2x125Ah battery bank that in turn supplies a pure sine inverter to give 240V AC for my appliances.

    I have a 240Vac main supply that I want to only use as a backup to charge the bank if the array can't maintain the bank due bad weather or excess drain.

    This relay: seems to be an appropriate way to provide a switch but can it be done so that the relay detects say 12.2V (25% battery capacity) & initiates mains recharge of the bank rather than waiting for the 12v to activate the relay because the inverter will shut down once 12V is reached and won't automatically switch back on.

    Any thoughts appreciated. I assume the relay should take a 12V direct from battery bank and 240v supply prior to connection to inverter. Any alternative solution appreciated