Anyone with electricity knowledge? Solar panelling a laptop off grid???

[VikingGirl]

Hi,

I don't like to bother you guys just with anything. But I'm really out of my league here.

So I've been researching on how to power a MacBook with solar energy for the last few months.. I've gotten nowhere.

Apple computers seem harder to pull this off with, but I just can't get used to Windows. So I would appreciate any indications or tip on how to suceed at this.
The issue with the Macs is their peculiar power connectors. Luckily I've got the last one that comes with USB-C, not MagSafe.

But then again, given is not generic, I haven't found many connectors out there to attach panels to computer, most panels(laptop panels) come with normal usb output. Not to mention Apple doesn't produce it's own car 12v connector either for this computer.

My electric dilemma is the following, "to second battery or to straight plug panel to computer"

Here is one panel that connects and it's made particularly for my computer: http://www.quickertek.com/products/cjuicz.html
My worry about this option is the voltage. From what I've researched, some people say voltages can spike on panels like this and fry the lithium battery or computer, which seems logical. I've email the supplier of the aforementioned panel about this, they haven't replied. I'm left to wonder is there's a voltage regulator or any other secure mechanisms built in the artefact or not.

Now using a second battery comes with other complications. I can just buy a generic and more powerful panel for the same price, store more energy. But the connection from the 12v battery seems complicated to me. First which battery to choose, lead are heavier but last longer than lithium, but the amps seems way to high and hard to smooth down to the 2A the mac charges at. My mac imput is 14,5v 2 amp by the way. Using an inverter seems foolish, going DC-AC-DC.. without mentioning the efficiency loss and the added heating from an inversor which becomes a firehazard in a wooden cabin. I really don't know, and I was wondering if anyone could guide me a little on how to achieve this.

I'd be so grateful. This forum is the best.
Peace. The Viking girl

 

[bopdude]

No idea personally but a quick Google found this

LINK

 

[SGL70]

Hi!

There are most certainly a voltage regulating circuit on board.

and a spike from a solar panel?...I am having trouble seeing what would cause a disabling spike.

I wouldnt have any qualms about using the linked product....a Mac is another kettle of fish, though

 

[Imagedude]

I'd go solar panel - regulator/charger - leisure battery - inverter - 230v charger.

 

[baggins]

We use a Power Gorilla with 2 solar panels linked in-line. This way, we avoid any potential spikes and, when the gorilla is full we have enough power for 2-3 hrs charge (from empty). We just use it to keep the laptop battery topped up. as far as i can tell it is the only one on the market that is 40 watts.
We also have a car inverter so we can give the batt and gorilla a boost when we are in the car.
2 weeks of camping this winter and we never ran out of power for 2 laptops (1 a mac), 2 phones, a portable speaker and rechargeable batteries for the tent lantern.
By reducing things like screen resolution and brightness, you can extend the batt life.

 

[Robson Valley]

The sequence in my solar power system is very conventional = solar panel then the charge controller then the deep cycle batteries then the inverter. Deep cycle marine batteries are designed for a lower floor voltage at "complete discharge" (mine are 10.5VDC) and charge to a maximum of 13.7VDC. I ignore their amp-hour rating, that tells me how much juice and for how long. For battery plate surface area to store the juice, I use two 6VDC in series and those pairs in parallel. An appliance which draws 2A is next to nothing. I recall that the inverter itself sucks 30 watts just to stay alive.

Inverters: the price goes up with complexity from square wave to modified sine wave to pure sine wave. I have used them all. I do not know if square wave equivalent of mains AC voltage can feed a computer power supply. I have a pure sine wave inverter which even has a couple of USB ports as well as a 12VDC port.

I'll go so far as to suppose that a voltage "spike" from a solar panel is a myth. While the efficiency might vary the amperage, the best they can possibly do (as mine) is 13VDC for 75 watts per panel.

 

[Bishop]

My electric dilemma is the following, "to second battery or to straight plug panel to computer"

If it's just the laptop to be powered up at a homestead then Solar panel array-> voltage regulator -> Laptop.

The L78S00 series regulators are cheap as chips and require only a few inexpensive external components to lock the voltage to a rock steady 14.5v@2 Amps. However you do need the solar array to produce more than 15v and that will probably require at least two panels connected in series. Some energy will be dissipated from the regulator but with a suitable heatsink bolted on it will be no warmer than a cup of coffee even on the sunniest of days. Any advanced Amateur radio enthusiast, tech geek or local electronics company should be able to knock one together. If anything it's an Electronics 101 project for a novice.

However UK sunlight sucks requiring a relative large (expensive) array to get a decent amount of power and an Apple laptop is a hungry beast. So I would consider moving over to a Raspberry PI based computer with it's way lower energy requirements. If it was any other laptop apart from a Macbook I would of suggested yanking the hard drive and going over to a 'Live Boot' from CD/DVD with USB thumb drives for storage as a way of reducing power demand.