SOLAR CHARGER

Q:

I keep my Boston Whaler 17 on a mooring. I want to keep the battery charged so as to keep the bilge pump running. The boat fills with water from rain if I don’t use it for a couple of weeks and if three or more days of rain occur. Being a Whaler, it does not sink, but I have to pump it out, which is a pain. Do those small, portable solar chargers work?

Abe Bettinois Portland, Maine

A:

Yes, solar panels absolutely work. Whether it will produce enough charge to replace the amps used by the auto bilge pump depends upon how much the pump runs and how much sunlight the panel receives. This is easy to quantify: A 5-amp pump running for two hours will use 10 amps, for example. So, a solar panel that puts out 5 amps will replace those amps for every two hours of sunlight.

Of course, we don’t know how much it is going to rain or for how long. Nor is there any way to tell how many bright, sunny days we will have—the panel’s output is reduced on cloudy days.

Still, a small solar panel works for many boaters in your situation. At a minimum, it will reduce the number of times per season you’ll be met with a dead battery and a swamped boat.