Solar Charging Question

[GreggS]

I have an Oday 25 that needs new wiring and charging system. A few long weekend trips would be my longest-duration on the boat before heading back to the mooring. The electrical house loads that I have planned include:

1. VHF
2. Bilge Pump
3. Composting Head
4. LED cabin lights
5. Nav Lights (LED)

That's about it. Maybe a few additional plug-in devices at most, so minimal load. I would like to put in a 100 or 200 aH Lithium Iron Phosphate battery, knowing that it will carry me through a 4-day trip without needing to charge. Then, while it sits for several days on the mooring, I would like to charge it with a small panel (about 20W), basically trickle-charging the system.

Is a panel this small going to be able to juice the battery, even over several days or a week?

Thanks
Gregg

 

[Leeward Rail]

Battery size seems overkill but you won't know much unless you determine the draw for those specific devices from their documentation.
Similar devices vary.
Do the calculations.

Random opinions mean nothing, especially when based on very little detailed info.

You also need to make sure that battery is installed correctly with a good BMS. Boat fires are not fun.

 

[Leeward Rail]

Read this and the linked page from "Mainesail"

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[Project_Mayhem]

On my O'Day 25 I had a 100w panel and an old deep cycle battery. It powered a small class D bluetooth amp, USB charging, voltmeter, LED nav and interior lights, bilge pump, VHF and engine starter (outboard starters draw even less than a Saildrive's). The batteries were always topped off within a few hours of solar charging. I'd go with a 50w panel if I were to do it again