Solar Powered Macbook Pro

[Littleodie914]

This question could probably be generalized enough to fit into the Community section, but since I'm asking it specifically for my Macbook Pro, I just figured here's as good place a place as any.

Nutshell: Do Apple's laptops/chargers require constant wattage to charge? If the wattage fluctuates, is any damage done to the battery/charging system, or does the battery just charge at a different pace?

I'm a huge gadget guy, and pretty big on renewable energy as well. I recently picked up a Solio Classic solar charger that I use for my iPods, iPhone, and Nook eReader. I'm completely hooked.

I'd like to go one step further and find a way to charge my laptop, and I know many solutions include:

Solar Panel <-> Charge Controller <-> 12V Deep Cycle Battery <-> Inverter

This allows you to charge during the day, then use the energy at night. (Or whenever.) It also provides constant power. (Both in terms of availability and wattage.)

Since that can get a bit more expensive, I'm looking to simplify things:

Solar Panel <-> Inverter

So my questions are:

1. Will this work at all? Can I just plug in a Macbook Pro charger to the inverter, and get a trickle charge while there's sunlight? (Obviously charging would cease when there's no sun.)
2. Do I need a 85W panel for a 85W charger? If I use the 20W panel, will it charge at 1/4 the speed? Or just not at all? (Given full sun.)

I work during the day on a separate machine, so I don't use my laptop for the 8-9 sunniest hours of the day. Here's to experimenting!

 

[blevins321]

I think I know the answer to half of your dilemma. BTW - I absolutely love the concept you're going for here.

Apple batteries are capable of trickle charging. Especially the more recent ones. An example is their airplane adapter that can charge when the system is idle, but serves as a supplement (battery still discharges but slowly) when the system is in active use.

Another example of this is that you can charge an iPad (10 watt) with an iPhone (5 watt) charger. It just charges the battery slower. What I don't know about though is how good the charger will hold up to different wall voltages.

 

[vexatia]

Curious to know if anyone else has experience solar charging Apple portables (egs Iphones, Macbooks, Ipads). If so, what do you use and what do you recommend. The Solio Classic looks alright but I'm having trouble determining whether it has any good competition.

 

[Littleodie914]

Curious to know if anyone else has experience solar charging Apple portables (egs Iphones, Macbooks, Ipads). If so, what do you use and what do you recommend. The Solio Classic looks alright but I'm having trouble determining whether it has any good competition.

I have a Solio Classic-i, and I've been pretty happy with it. In my opinion, it's the best portable solar charger for small devices you can get. But, personal solar tech is still pretty new/inefficient, a few things to note (specific to the Solio Classic-i):

1. It won't charge a laptop. The largest device I think it would reliably charge is an iPad, and I would estimate that with a full charge on your Solio, you'd get the iPad to 40% or so. It charges my iPhone to about 70%, and almost completely charges my Nook eReader.
2. MAKE SURE you get the "-i" model. For example, don't get the "Classic", get the "Classic-i" It's very difficult to tell what the difference is at first, but it's huge. The older (non-"i") models come with 5 tips, and that's all you get. Period. The newer "i" models charge via the "iGo" tips, of which there are literally hundreds. One for any device, and super cheap on Amazon.
3. It takes a while to charge. If you take it to the beach with you all day and leave it in the sun, you'll probably get around 60% charged.

 

[ender land]

How much energy does a mbp use (on average)?

My guess is that 20W of power would not be enough to actually power and run a mbp simultaneously. Not to mention that assumes the cells are generating a full 20W and that none is lost in the inverter, which are likely both not true.

If it was sleeping or off, my guess would be you'd slowly charge it (obviously much, much slower).

 

[Scuby]

Big caveat that I haven't tried this myself, but...

Have a look at the MagSafe Airline power adapter. It runs off (apparently) 15V input rather than 120-230V, which should remove the need for the inverter, and so avoid a lot of the associated power loss - you lose a lot stepping up from the solar panel, to 120V, which the charger just has the step down again. Would also make your setup much smaller. But you'd have to look at the specs of the airline power adapter, what voltage / current it expects, and make sure your solar panel will provide that.

Seems like it would be a more elegant solution though.

David

 

[solarmac]

I searched high and low to find how to run my MacBook Pro using solar power. We are travelling for many months across the desert and hence can't rely on power outlets. Only finding incomplete information, I decided to put together a very detailed guide on the science behind solar powering a MacBook and the options (with prices) available, depending on how much you want to 'do yourself'.

HOW TO: Use Your MacBook with Solar Power

http://globetrooper.com/notes/solar-power-macbook

Would love feedback and to know if you learned anything rom the article. I put a lot of effort in it to help others struggling to find practical and useful information.