Is a five watt solar panel enough to keep the battery charged. All I have is the VHF radio and cabin and running lights.
solar panel
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five watts is less than half an amp at 12v, that will work out to 2 AH of power per day. (.4 * 5 hours full sunlight) or 14AH/week
You need to figure out your average power usage per day. That will answer your question.
You need to figure out your average power usage per day. That will answer your question.
I have a 5 watt solar panel I have used for the past 3 years. Have yet to run out of power. I did however, change all the bulbs on my boat to led's. It was somewhat in-expensive. Found all the bulbs I needed at the following link. www.superbrightleds.com good luck
I'm saving my allowance for this:
http://www.batterystuff.com/solar-chargers/SCC015.html
While I'm gone, I just want it to keep the battery charged to run the bilge if needed. When I'm there, I want it to run my gps/sonar/chart doohickie, cabin lights
http://www.batterystuff.com/solar-chargers/SCC015.html
While I'm gone, I just want it to keep the battery charged to run the bilge if needed. When I'm there, I want it to run my gps/sonar/chart doohickie, cabin lights
VHF in standby mode probably draws 0.5 amp, each light would draw around 0.5 amp.
Sooooo
If the panel puts in 0.4 amps during 5 hours a day that would cover the VHF for the daytime. The rest of the power would have to come out of the batts.
This is not a solution for 'everyday use" You would need a bigger panel
If you are only using it during the weekends then the math works like this
0.4 amps X 48 hours = 19.2 AH for the VHF for the weekend
2 lamps X 0.5 amps X 5 hours X 2 days = 10 AH for the lights for the weekeind
Total 29.2 AH used over the weekend --> you could do this pretty easy on a 50 AH battery
The solar pane is putting out (if the sun shines every day all week long) 14 AH.
Conclusion, you will be draining your batts with this panel by 15.2 AH per week. That does not include any engine alternator contribution.
Sooooo
If the panel puts in 0.4 amps during 5 hours a day that would cover the VHF for the daytime. The rest of the power would have to come out of the batts.
This is not a solution for 'everyday use" You would need a bigger panel
If you are only using it during the weekends then the math works like this
0.4 amps X 48 hours = 19.2 AH for the VHF for the weekend
2 lamps X 0.5 amps X 5 hours X 2 days = 10 AH for the lights for the weekeind
Total 29.2 AH used over the weekend --> you could do this pretty easy on a 50 AH battery
The solar pane is putting out (if the sun shines every day all week long) 14 AH.
Conclusion, you will be draining your batts with this panel by 15.2 AH per week. That does not include any engine alternator contribution.
I,ve used the 15 watt solar from batterystuff .com that sublime is saving for, for 3 years now.Keeps two 27 batteries in parralel hookup fulling charged.Anything over 5 watts should have controller or you will overcharge is what I,ve been told.I run Marine radio,Stereo ,cabin,running lights,Fan,12 v cooler.
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I have been OK with just that charger
I have used a trickel charge solar panel for years and it has kept my battery charged except for one time. However, essentially I evening sail 2 times a week for about 3 hr each and/or weekend sail for about 3 hr on saturday or sunday. (it is a small lake) I run my vhf all the time and navigation lights at night. So my amp use is low enough that the charger keeps up. I also leave it hooked up thru the winter. It charges the battery right through the tarp that covers the boat.
I have used a trickel charge solar panel for years and it has kept my battery charged except for one time. However, essentially I evening sail 2 times a week for about 3 hr each and/or weekend sail for about 3 hr on saturday or sunday. (it is a small lake) I run my vhf all the time and navigation lights at night. So my amp use is low enough that the charger keeps up. I also leave it hooked up thru the winter. It charges the battery right through the tarp that covers the boat.
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