Solar

[walt]

Ill just point out one more slightly important thing to consider if your using a small panel...

There is a spec that tells how much current the controller uses just to operate. For example, the SG4 uses 6 ma and the 20 amp one in the link uses 30 ma.

Since that self powering current is on all the time, it can add up and be significant.

At 6 ma, the self consumption of the controller over 24 hours is .144 amp hour. If we assume 5 hours of sunlight, it takes about .5 watts of your solar panel just to power the controller. Not such a big deal with a 10 watt panel.

At 30 ma self consumption (what the 20 amp controller has), the 24 hours self consumption is .72 amp hours. That now takes 2.44 watts of solar panel just to power the controller. No big deal if your panel is 50 or100 watts but with a 10 watt panel, 25% of the output is going to just keeping the controller turned on.

 

[Cruiser1]

Ill just point out one more slightly important thing.............
There is a spec that tells how much current the controller uses just to operate. For example, the SG4 uses 6 ma and the 20 amp one in the link uses 30 ma.

Since that self powering current is on all the time, it can add up and be significant.................

At 30 ma self consumption (what the 20 amp controller has), the 24 hours self consumption is .72 amp hours. That now takes 2.44 watts of solar panel just to power the controller. No big deal if your panel is 50 or100 watts but with a 10 watt panel, 25% of the output is going to just keeping the controller turned on.

Thanks for pointing that out Walt (and for contibuting to my electical education!). Looks like the decision to stick with the SG-4 has now been confirmed.

 

[Kestle]

Nice article in Sail Magazine about shadows on panels.

Jeff

 

[vizwhiz]

Nice article in Sail Magazine about shadows on panels.

Jeff

Yeah, I read that, and was going to point that out too...I thought it was quite informative, and really pretty surprising!