Solar Panels for boats

Using a Solar Panel for a boat

Lake Travis in Austin Texas is about 40 feet down right now with over 50% of the water gone. That’s not good! But also it’s not good because they’ve pushed out the docks so far that the marina company no longer supply electricity to the dock. This left a highly disappointed crew last week when we went to go out – the batteries were flat on our 37 foot Beneteau. Grrrr!

Enter technology! Today I received in the mail a 7 watt solar panel – it’s about 14 inches square.

Solar Panels are a perfect solution for no electricity at the dock

Solar Panels are a perfect solution for no electricity at the dock

I bought it from Defender – who are a major chandlery supplier in the USA

Here’s the link|328|2290044|2290048&id=2363892

I’ll head out to the boat this weekend to install it.

Just doing a little math here – at 12 volts, this solar panel will pump out about 1/2 an amp (0.583) (Watts = volts x current). An average battery holds 90 amp.hours of energy. That means we need to put in 90 amp.hours of energy to fully charge it – at 1/2 amp that will take 180 hours – or 22 days (8 hours per day of sunlight) .  Whoops that is not so good but we really don’t need it topped off to get enough energy to start the engine.

We’ll run the experiment and report back here – stay tuned. Just blind intuition says about 3  days will do it.

Solar panels are best used to keep a battery topped off not for a full deep charge. They are especially useful for boats that do not have an alternator charging the battery i.e. boats with outboards. The solar panel in this situation will help keep your house batteries fully charged.

Solar panels for boats are in expensive – around $50 and well worth the reduction in frustration.

Stay tuned to this experiment.

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My vision for NauticEd is to provide the highest quality sailing and boating education available - and deliver competence wherever sailors live and go.
Grant Headifen
Last updated on July 12th, 2022