Our new 320 watt solar panel - Isn't she beautiful?
Last year our energy management plan included using our generator to recharge the batteries every third day. It worked pretty well when we hopped from marina to marina with one or two days anchoring or picking up a mooring ball in between. It even worked when we were on a mooring ball in Hope Town for a week last year. But, as we sailed/motor sailed down the west coast of Florida to Marathon, we realized that keeping the batteries topped off would require hours and hours of generator time. In fact, we were initially concerned that our batteries had been damaged during the summer when the battery charger had been off due to electrical outages for extended periods at the boat storage yard.
We were extremely concerned about going to the Bahamas with such a limited way to generate power and keep our refrigerator going. And as I now know, the whole electrical process on a boat is hard to get your hands around. We have an alternator that lets the batteries charge from the engine when it is running and a battery charger that charges the batteries when we are on shore power or the generator is working. There are certain items on board that work off 110 volts AC (shore Power/generator) and certain things that work off 12 volts DC straight off the battery. Being the daughter of an electrical engineer you would think that I would have had a basic knowledge in this regard – but NO – all new to me. Marina hopping I never gave this much thought – it was part of Bob’s realm.
After numerous conversations with very patient people who provide technical support from the companies that sold us the alternator, the batteries and the battery charger, and after moving over to a marina so that we could recharge the batteries (on shore power) and then have them without any load for six hours, we concluded that our batteries were not damaged. This meant that our means of recharging them – the generator – was just not going to be enough for extended times on anchor or mooring ball.
DON’T READ THIS IF SCIENCE IS NOT YOUR THING – JUST SKIP TO NEXT PARAGRAPH
When you first charge batteries that are run down say to 60% of their total capacity, the charging source operates in the bulk stage and the batteries acccept a higher number of amps. As the batteries approach full charge the charger goes to absorption stage and then to float. When in absorption the batteries accept a lower number of amps because they know they don’t need as much to get to full capacity and then in float an even lower number of amps. With the generator we were passing to absorption rather quickly so that a lower number of amps were going into the batteries per hour which is why it would take a very long time to fill a 300 amp battery bank.
So, what was the answer? Solar of course – there is a reason that almost every other sailboat in the BootKey harbor has a solar panel on the boat. It works! I can’t tell you why we thought we would be different and not need it. I know that initially we were trying to keep our costs down and having not cruised other than marina hopping on the Great Lakes, we just didn’t have the experience. Unsolicited everyone recommended the same guy to talk to about solar panels in Marathon. To make a very long and anxiety producing story short - we called Alex. He explained how much solar he thought we needed for our 300 amp battery bank and believe it or not he had a cancellation that day and in 4 hours could have everything installed. I think we believed this was message from “above” because you seem to have to wait a ong time to get anything done on a boat. By 3:00 pm that day we had our 320 watt solar panel installed. Needless to say from the time we first spoke with Alex until the time we gave him the go ahead we were checking reviews, talking with friends who had panels and trying to get as much knowledge as humanly possible.
In the three days since the install our lives have changed. No more constant checking of the battery status except to see the miracle of how many amps we are putting in from the solar panel via an app that we both have on our phones. Life just got simpler. Even yesterday when it rained and the wind blew like crazy – we used the generator to make a bit of water and then in the AM - the solar topped off the batteries to 100% in the afternoon. You gotta love it!