Experiments with the solar gorilla
I read loads of reviews of the solar gorilla before taking the plunge and buying one. I payed particular attention to mentions of the macbook (being my weapon of choice). One thing I noted was that when using the solar gorilla with the apple airline magsafe adapter, the reviews all pointed out that this would only power, not charge, a macbook. I was wondering if this was a limitation of the adapter, or insufficient power. I read somewhere that it was the former, so decided against buying an airline adapter (I had plans to make my own 12v plug adapter to link up with my butchered magsafe adapter). However, after speaking to powertraveller, they said they could send me a "sample" magsafe adapter, which connects directly to the power gorilla.
My first attempt to use it (by sticking the solar gorilla out on the roof on a cloudless day, but setting sun), and the charging status read "charged" (starting from a charged battery), but after running for about half an hour, the sun went behind some houses and the status changed to show it running on battery, which was now pretty flat, so the macbook had indeed been running from battery the whole time.
The second experiment today in the back garden, starting from a 50% full battery, the macbook status read "not charging". There are a few clouds around, but it is a rare fairly sunny june day. I think I can therefore conclude that the solar gorilla is not a viable charging or powering option for a macbook in a UK climate when used on it's own.
One question still open is whether the sample magsafe cable has the same limitation as the airline adapter - i.e. is it supposed to charge? To work that out I will try it with the power gorilla (waiting for me at olivewood HQ). If that doesn't work, I will cobble together the DIY solution mentioned before, to rule out wiring.
I have worked out that it is possible to have the solar gorilla charging my leisure battery, while I simultaneously power/ charge the macbook via my DC-DC converter. I've yet to work out what rate the battery is being charged vs drained! Another concern is that I seem to have one of the earlier generation of solar gorilla (it has a green, rather than red LED), which possibly suffers from reverse charging i.e. in theory if I leave connected to the leisure battery after dark it might drain it - still inconclusive though.
Another annoyance is that the solar gorilla will not even charge my iphone when connected to the usb port. This is probably due to the "fussiness" of the iphone, probably a fluctuating or insufficient voltage causes the iphone to declare "This accessory is not supported".