Solar panel wattage

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Joined: Fri Oct 09, 2015 9:25 am

Solar panel wattage

Postby Drifter » Mon Nov 02, 2015 10:11 pm

Hi All,

Happy to report I took my new C18 out for her first sail today and had a ball! I am planning on going on the middle harbour cruise later this month and am seriously considering getting a solar panel to charge the small deep cycle battery - Remco 18Ah battery - to charge phones etc. There is also an autopilot which I am keen to try out but don't want the little 18 Ah battery dying half way through! I have done a bit of reading and research here and elsewhere and understand it's important to have a diode to avoid the solar panel draining the battery however since the battery is so small what is the best size solar panel for the job? Seems 5 or 10 watts is the max as most have a minimum AH capacity of the battery. Have looked and spoke to staff at Whitworths and Jaycar but they don't seem sure of the panel size I should be looking for. Many thanks for advice.


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Mark III Amigo
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Re: Solar panel wattage

Postby Mark III Amigo » Tue Nov 03, 2015 2:46 pm

I have a 45AH deep cycle to power my electrics, which includes interior light, Nav lights, radio, sounder, 12V cig charger and auto pilot at times. The pilot does suck a bit of juice and I think the 45 is a bit under for all the work it has to do. I have a 10W panel and no regulator. Most panels come with the diode fitted.

Land Lubber
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Re: Solar panel wattage

Postby Mick » Thu Dec 17, 2015 11:26 am

Having had a lot to do with solar charging, I would advise you to check the amount of amp's drawn by things like the auto pilot.
Amp's X by Volt's gives you Watt's, double the the watt's and fit a regulator as solar panels seldom put out listed rating due to angle of the sun.
I have found the best prices for both solar panels and regulators to be online and have some in use every day. 4.5 ton motorhome
and backup power for the house fridge-freezer-lighting via pure wave inverters and deep cycle batteries.
The 18 AH AGM batteries work very well as I use 1 in both of my BMW K100 motorcycles.They work at any angle and use little space.
Would fit 2 in the yacht tho just to be sure and change all lighting to LED.

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