Old 10-07-2020, 07:24 AM
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Join Date: Oct 2019
Posts: 395
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I would use 2 Group 27 dual purpose. That's what I have on my 20' w/Yam 150. I've always been told the batteries should be the same or you'll throw off the charging system. Not sure how much fact was behind it, but it came from a supposed "battery guy". The reason why a lot of the AGM are Dual is, for the most part, you want to have a "back up" for starting and the standard Deep Cycle won't do it. In my double setup, my normal routine is to run #1 on the Saturday and #2 on Sunday. If I sit with the engine off for more than an hour and something running, then I'll put my switch in "both" if she tries to drag a little at startup, but rarely do I need to. This routine has worked pretty well for me and keeps both batteries in-use and sufficiently charged. Of course, I'm a stickler for charging at home the night before too.