Maplins 13 Watt solar briefcase.

[mickywillis]

I have one of these: http://www.maplin.co.uk/13w-solar-briefcase-99760
purchased last year and only used for the first time this weekend.
And then it was damaged whilst sailing back to Langstone from Ryde. It fell from its store on the forward berth, hit the floor and now has 2 very large cracks across the entire face of one of the panels.
I've put a Wanted ad on the site for a replacement panel, but no interest as yet.
When I used the panel in yesterdays sun, I was getting an output from both panels of 22 Volts DC and an output current of 0.5 Amps DC. So if my calcs are right, P = V x I, 22V x 0.5A = 11 Watts? Putting a 5 Watt, 12V automotive bulb across the wires made the lamp glow correctly, but the panel would not light a 10 Watt lamp? Do these figures sound right or do the cracks in the single panel appear to have reduced the output power to only 1/2 the stated wattage?
Will the cracks in the second panel be detrimental to the entire output of the whole suitcase or should I continue to use it? To stop the glass becoming dislodged any more, I'm thinking of covering the cracked panel with a thin sheet of clear perspex/acrylic sheet or a clear self adhesive film, what do you think would work best?

 

[William_H]

I am not sure that the test using a 10w bulb is significant to indicate serviceability of the panel. Bulbs tend to have a very low resistance when cold and conceivably the panel cannot provide enough current to get the filiament hot enough to get it into the correct resistance spec.
So the .5 watt into batteries is all that really matters and means the panel is essentially working correctly.I would suggest that with the crack in the panel moisture getting in will be an ultimate killer of the panel. You can often see the corrosion creeping in from the crack or edge. I would suggest perhaps some epoxy or silicon worked into the crack to try to seal it. Plus perhaps the perspex cover you have in mind.
A question you might like to answer is whether each panel is 20v connected in parallel or if each is a 10v panel connected in series. If it is the former then you may be able to use it as a 6w panel if and when the damaged panel dies. Sorry about your heart break at damaging the panel, yes I have done it too. good luck olewill