I have Calder's book, but with the Echo-charge, you don't actually connect your typical charger to the starting battery. The echo-charge connects the house to the starting battery and will sense a charge on the house (from your charger, alternator, solar, etc.) and then float some of that charge over to your starting battery to top it off.
The instruction manual on the echo-charge says this:
"Only similar batteries should be connected together in one bank. Do not
connect old and new batteries together or wet and gel cell batteries
I think that this is referring to a bank and not the entire system. If so, I can use an AGM dual purpose for the starting battery. Anyone?
My engine is the Yanmar 4JHE (about 45hp). The manual doesn't spec out CCA or MCA, but does say that you want between 100 and 150 AH. I think for starting, I need to be concerned about Cranking Amps. There is a Group 24 dual purpose AGM at WM with 735 MCA. Anyone know if i can use this as a starting battery for this engine? (This is assuming that I can use an AGM with the echo-charge).