Solar Power

[Greg]

I was looking at a small solar panel to keep the battery charged. I saw one that was 5 watts and a smaller one that’s 1.? watts... will the smaller one work or would it be better to just get the bigger one?Any Ideas?Greg s/v Passin' Wind

 

[Miles]

Bigger IS better...

I'd say get the larger panel, no one ever complained about too much power... Not sure what size battery you have but I doubt a 1 watt panel would be good for much of anything. A 5 watt panel should float a medium sized battery pretty well and may even charge it a bit. We've got a 32 watt panel that does a good job of actually charging our 4D batteries but I wouldn't mind having an even bigger one. As long as you've got room for it I'd get the bigger one and a regulator if the panels output is more than 1% of the batteries capacity (measured in AH). Have fun!

 

[John Paoletti]

Solar ideas

Here are a couple web locations for you. I bought an 11 watt Siemens for $100 on the net. Search and you will find. Good luckhttp://www.solar-electric.com/solar-panels-1-to-39-watts.htmlhttp://www.batterystuff.com/battery/solar_chargers.htm#10W%20Panelhttp://www.clearsolar.com/138/cat138.htm?580

 

[Alan Long]

I have a 10 watt Siemens rigid panel on my 23.5 with two Group 27 batteries. This is the first year of usage, but it seems to be working fine. We stay onboard for a weekend using lights, fans, and depth sounder. The boat usually sits for two weeks or more before we use it again. So far the batteries have been well charged.Alan LongS/V Random Access

 

[Tim Schaaf]

another source

Another web site with really great prices is solarelectricinc.com, not to be confused with solar electric.com

 

[Bryan C.]

Panel sizing

The panel size you need depends upon the size of the battery bank you want to keep charged. For trickle charging -- just keeping your battery topped off, you want you panel to put out about .5% of your batt's amp hours. So if you have a 200 amp hour bank, you want about a 1 amp trickle charge which is about 15 watts. (15 watts / 15 volts ~ 1 amp)If you want the solar to recharge your batteries, like the others say get the biggest you can, but you'll also need to wire in a voltage regular so they don't fry your batteries. Smaller regulators are not expensive, can be found for $20-40.

 

[Keith Smoot]

5 watts is enough if you have enough time

I have two 31AH batteries on my H-23, Gwaihir. I use a 1-2-both switch to charge either or both batteries with a 5 watt solar panel from a hardware store. Given that I usually sail once a month in the summer and slightly less often in the winter this works for me. I also have a Gell/Wet Cell charger just to make sure or for quick turnarounds.