Originally Posted by btrayfors
Well, yes and no. So long as the EchoCharge is sensing more than 13.0V on the main bank, including a "float level" of 13.2V or more, it will continue to pass some current to the auxiliary bank.
So, the answer to the OP's question is, YES, it will maintain the standby battery just fine.
A battery bank not receiving a charge will easily drop below the Echo turn on of 13.0V and the Echo will then shut off. 13.0V is a surface charge only and a full
battery is about .3V below that.. If the battery was not full when the other bank stopped charging the bank fed by the Echo may not get full..
If the other bank is getting no charging it won't hang out above 13 volts very long especially with the Echo lightly loading it... It might stay above 13V for an hour or so, depending upon temp and how much the Echo is trying to pull, but that's about it..
I suspect Steve might do well to invest in a good controller that goes into float rather than shutting off completely.. If we knew what controller he has and the size of the array we could be of better assistance..