Rick Hurst Web Developer in Bristol, UK


Category: macbook

Experiments with the solar gorilla

Solar Gorilla on the roof

I read loads of reviews of the <a href="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”.

Preparation – keeping a laptop charged on the move

I have been buying and experimenting with some equipment to help keep my laptop charged while i’m away from mains electricity. I have few tools at my disposal:-

Halfords Portable Powerpack 200

Halfords Portable Powerpack 200

It’s basically a 12 volt leisure battery with a lamp, 240 volt inverter and air compressor built in. I only got it because I inherited it with the car (the previous owner bought it to jump start the car when it had been in storage too long and the main battery had gone flat). It can charge from a 12 volt car socket or mains adapter, plus I am having some success charging it from a solar gorilla. The battery sais that it is 20ah, whatever that means in lamens terms.

Using the 240 volt inverter is incredibly inefficient, so only for “emergencies” really. More efficient is using the 12 volt output with the Trust DC-DC converter (below) that allows me to step up from 12 volts to the 16 volts required to run my macbook.

The obvious downside of this battery is that it is very heavy, only suitable for lugging around in the back of a car, so while it will be useful on a campsite with no mains hookup, i’m not exactly going to lug it into a cafe!

Trust 130W Multi Function Notebook Power Adapter

Trust 130W Multi Function Notebook Power Adapter

This is really useful – if I wasn’t a mac user, there would probably be a charger tip included with this, but due to licensing there isn’t. Therefore I had to take the DIY approach of snipping a section of cable from my spare apple power adapter (doesn’t feel good doing that, knowing they are about £60 to replace!). I also modified one of the tips to allow me to fit a section of wire with spade clips, to make it easier to plug in other adapters if necessary.

Amazingly this works – charging and powering the macbook. I need to do some proper experiments to see how many charges I would get out of the leisure battery.

It also has a USB port so I can charge my iphone from it at the same time.

More details on the dealer’s site.

Solar Gorilla

solar gorilla

This is a lightweight portable solar panel that will apparently charge a laptop. Covered in more detail here