Solar experts please.

[john_morris_uk]

I’ve read lots about solar but I’ve no experience and I’d like some advice please. This is for our daughters Pandora 700 so think small! The boat will be on a swinging mooring so no shore power.
One 1Ah battery supply’s everything.
Charging is going to be from a Tohatsu 6hp sail drive so only a few amps. The plan is to supplement thus with a solar panel.

Drain is:
VHF radio. 1amp on max volume on receive but mostly 0.3 amps. Transmit time is negligible.
Instruments 0.05 amps
LED lights all round. (If everything was turned on still less than an amp.

Edit: She says she wants to have at least one (if not two) phone charging sockets.

No autopilot atm but I can’t imagine her being without one for ever.

Calculations suggest 30 watt panel might be enough. Let’s call it 50 watts? The boat will sit on its mooring most of the week most of the time. It would be good for her to arrive and find the battery at or near 100%

MPPT Controller?

Any suggestions or any ideas?

Edited again to correct a couple of figures.

 

[Black Sheep]

I would think that 50 Watts will be plenty. I have 40W on my 18 footer and that's enough to drive that amount of kit, plus Raspberry Pi navcom and a tillerpilot through the spring & summer. It might be different if she's doing a lot of winter sailing.

A boat that size, the limiting factor is physical space, so best quality panels and MPPT controller. If she's able to fit rigid flat panel, then do so (more efficient & cheaper) otherwise a good quality semi-flexible.

I found Photonic Universe a supplier of good kit, but also used Sunrise Energy on Ebay.

 

[JumbleDuck]

I have a similar size of boat. I suggest that you/she fit the biggest panels you reasonably can in the space available. Having extra power available never harmed anybody , and she may want to charge a phone/tablet/laptop. We have 120Ah and 100W which works fine. I don't think there is much point in MPPT unless you have biggish panel, but they seem to be only a bit more expensive than PWM now so if £30 extra isn't a problem, why not? Maybe one of these 12V solar panels charging kits for caravans, motorhomes, boats, yachts, marine in which case yet another £30 for the remote display could be money well spent.

 

[Black Sheep]

another £30 for the remote display could be money well spent.

Ah yes, it's a good point that being able to see what's going on is a big help. I have a digital voltmeter and ammeter on my switch panel which lets me easily see the state of charge, and be able to check what's eating the amps.
I'm fitting out my 29 footer to inlcude monitoring of the controller from a mobile phone by bluetooth. It's lovely in its way, but mainly to see historic data; apart from that, a bit OTT, IMHO. Volts and amps should tell you all you need. In fact Volts alone is the critical thing.

 

[Jamie Dundee]

Another vote for 12V solar panels charging kits for caravans, motorhomes, boats, yachts, marine Worth getting one of these, cheap enough.

 

[john_morris_uk]

I take your point about monitoring but I’ve queered the pitch by recently buying and installing this:



The teak panel with trim is not me showing off my wood bodging skills but is there to hide a bigger hole underneath.

 

[john_morris_uk]

Here’s the battery with its fuse and shunt





Strapped in to hopefully make the surveyor happy.