I'm in the process of refitting a 1968 29' Quorning Trimaran
with some friends, and we really want to get a solar
setup that can at least keep the batteries topped off when in the slip and also at least extend the life during 3-4 day weekend type cruises. This is a pretty old boat, so we have pretty low power
requirements, one small GPS chartplotter
that is sometimes used when not utilizing an iPad
, a tiller based autopilot
, and a LED tri-color mast
nav/anchor light, nothing else to speak of. We are hoping to add a small portable style refrigerator
under 20L total capacity that we would run from time to time to keep some perishable food
cool when necessary. We are in Denmark
, so even during the summer the temperatures do not get excessively hot.
We are hoping to get to around 150-200w w/ MPPT
, but we'd like to avoid heavier rigid glass type panels
hanging off the boat. The owner prefers to have one permanently installed semi-flexible panel in the curved area amidships just aft the mast
which is 70cm x 80cm (27.55in x 31.49in), and then use an additional stow-able folding panel that we can pull out when mooring
or at anchor
Our boat is a 12v setup with only around 100Ah bank currently, I *believe* the chemistry is lead acid or AGM
, definitely no fancy li-on/LiPo banks here, but will have to check next time I get a chance on the specifics.
I'm no electrician, but my main concern and question is how to handle the addition of a separate "portable" panel into the setup? Most MPPT
controllers I see only allow one input from the panels
, and even if we were to permanently install these I presume we cannot do them in parallel due to the specs of the panels likely being different. Does series work here? If so, are others using some sort of permanently installed relay or junction box setup that allows you to plug
in some MC-4's that you then switch over and now the permanent panel *and* portable panel are wired in series with a bypass diode? Do you run a completely separate controller just for the portable panel? Something else?
Just looking to get on the right track here, so I know what we should be looking for, so I'd love to hear comments. I'd love to hear feedback on the setup idea the owner has, as well as if anyone can recommend a semi-flex panel that will fit within 70cmx80cm. We have been looking at the Rogue MPT-2024 controller due to flexibility with regards to expansion especially if we decide to move to a larger boat.