I hate hauling my battery home for recharging, and do not have access to AC where I moor. I recently borrowed a friend's solar panel for a 3 day cruise, and was delighted when the VOM indicated a higher charge when we returned than when we had departed. So I am very interested in purchasing one. How do I buy enough, but not overbuy / overspend? As far as usage goes, mostly we day-sail, with depth finder / knot meter running. We often come in after dark, using our running lights for an hour or so. How do I determine what size solar panel I need? Thanks!
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Jay Beery
Go Solar!
I have a C22 with a single 12v battery. So far I have found a $60.00 battery maintainer in the cabin window just right. I run a fishfinder and radio/CD player for a few hours a week and do just fine.
I have a C22 with a single 12v battery. So far I have found a $60.00 battery maintainer in the cabin window just right. I run a fishfinder and radio/CD player for a few hours a week and do just fine.
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Don Evans
Panel Sizing
Add up your draws, for example 2 amps per hour over an 10 hour sail, equals 20 amps. Factor in the inefficiency of the panels (bad panel angle, cloud, latitude... say 50%), and the number of days between sails (1,2,3,4,5,?). If the rated output of a mid size panel is 1 amp X 4 hours of charging (this is the efficiency factor of panels), thats 4 amps of juice X #days, say 5 days between sails, you will have replaced all your battery draw (the 20 amps used from the previous sail). Panels are also rated in watts, as are appliances and electronics, but amps is a convenient unit as batteries are usually sized this way. In solar charging, bigger is usually better. Depending on your battery capacity, anything over 2 amps of charging should be voltage regulated to prevent overcharging of the battery. Hope this has helped. Don
Add up your draws, for example 2 amps per hour over an 10 hour sail, equals 20 amps. Factor in the inefficiency of the panels (bad panel angle, cloud, latitude... say 50%), and the number of days between sails (1,2,3,4,5,?). If the rated output of a mid size panel is 1 amp X 4 hours of charging (this is the efficiency factor of panels), thats 4 amps of juice X #days, say 5 days between sails, you will have replaced all your battery draw (the 20 amps used from the previous sail). Panels are also rated in watts, as are appliances and electronics, but amps is a convenient unit as batteries are usually sized this way. In solar charging, bigger is usually better. Depending on your battery capacity, anything over 2 amps of charging should be voltage regulated to prevent overcharging of the battery. Hope this has helped. Don
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LaDonna Bubak - CatalinaOwners
Regulator
As Don mentioned, anything that will put out more than just a trickle charge (Jay's charger is probably considered a trickle charger) should be regulated. Regulators will prevent your batteries from burning up and are NOT just an option. I have a super duper old panel that's enormous but works just fine. It's barely puts out 2 amps so I don't have a regulator but I also don't leave it hooked up all the time - only when I'm using DC. LaDonna
As Don mentioned, anything that will put out more than just a trickle charge (Jay's charger is probably considered a trickle charger) should be regulated. Regulators will prevent your batteries from burning up and are NOT just an option. I have a super duper old panel that's enormous but works just fine. It's barely puts out 2 amps so I don't have a regulator but I also don't leave it hooked up all the time - only when I'm using DC. LaDonna
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Brad Williams
Richard, go w/a 10 watt
I throw that size out for a couple of reasons -- one it sounds like that would about do for what it sounds like your needs are; two, a 10 watt shouldn't need any regulator as it's small enough not to overcharge the battery; and three, a 5 watt isn't that much cheaper and only provides half the output. Notwithstanding everything Don told you about sizing, you don't need to go through the excercise with a minimul draw such as you have. For a little one like that, I like the flexible ones -- not much difference in price and they just seem to me to be more handy. That's a matter of preference. Some will say (true) that the rigid models can be mounted out of the way back on the pushpit. And, the rigids (I think) perform a little more efficiently (slightly smaller for the same wattage bang). Whatever you do, don't run down to the local West Marine or whatever store and buy one......they are dirt cheap at places on the net. I've used a place in Arizona -- and, no, I'm not associated with them or anyother bunch. windsun.com/PV_Stuff/solar_electric.htm Anyway, solar is the way to go. Good sailing. Brad
I throw that size out for a couple of reasons -- one it sounds like that would about do for what it sounds like your needs are; two, a 10 watt shouldn't need any regulator as it's small enough not to overcharge the battery; and three, a 5 watt isn't that much cheaper and only provides half the output. Notwithstanding everything Don told you about sizing, you don't need to go through the excercise with a minimul draw such as you have. For a little one like that, I like the flexible ones -- not much difference in price and they just seem to me to be more handy. That's a matter of preference. Some will say (true) that the rigid models can be mounted out of the way back on the pushpit. And, the rigids (I think) perform a little more efficiently (slightly smaller for the same wattage bang). Whatever you do, don't run down to the local West Marine or whatever store and buy one......they are dirt cheap at places on the net. I've used a place in Arizona -- and, no, I'm not associated with them or anyother bunch. windsun.com/PV_Stuff/solar_electric.htm Anyway, solar is the way to go. Good sailing. Brad
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Richard Laribee
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Dan Benson
I have your precise answer
Request a catalog from Jack Rabbit marine at 203 961 8133. The catalog provides a wealthe of information regarding solar,wind, and water power and specifically answers your question regarding solar panel sizing, power needs, etc. Dan Benson flatpickindan@yahoo.com
Request a catalog from Jack Rabbit marine at 203 961 8133. The catalog provides a wealthe of information regarding solar,wind, and water power and specifically answers your question regarding solar panel sizing, power needs, etc. Dan Benson flatpickindan@yahoo.com
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