Auxiliary charging lead

[PCAguon]

Is it possible to use this auxiliary charging lead to 2 house batteries connected in parallel? Should the lead be connected to the 2nd deep cycle battery which is not connected to the house system, or the 1st deep cycle battery that is connected to the house system, does it matter? These batteries make up my second bank (house) in parallel, i have a separate battery for the starting battery and lead

[Harper]

I don't think it would make any difference and should work. There's nothing in the setup manual that indicates that both batteries in the dual charging setup have to be the same number of amp-hours, and by that's essentially what you're doing by connecting two house batteries in parallel, just doubling amp-hour capacity at 12VDC.