portable solar charger for my laptop(I have to carry it)

[calumbo]

Hi All,

I am trying to design a solar charger for my laptop and this is how far I have got.

solar panel (What size)?- Charge controller (what size)- Battery (12v 7AH) i already have this but could buy something new- Either DC-DC converter or a power inverter- Laptop 19VDC, 3.42A, 65W)

I just want to do my bit for the environment and I believe this would be a start. If someone has already set this up it would be great to get a picture or diagram. I need help with the whole thing or how to decide what ratings,sizes I need for all the components.

Thanks in advance and I have to say I'm a complete novice at all this.

[PNjunction]

You didn't mention how long you plan to operate.

The money you'd put in to do this right would be better spent on just carrying spare batteries, or better yet, a tablet and an Anker 14 watt panel which connects directly to the tablet. Or it can also charge external Li-ion packs. Also found at Anker.

It makes little sense these days hauling around all the gear you need for a proper running laptop when a tablet would do it much easier.

[calumbo]

Hi,

thanks for your quick reply.

Sorry I should have mentioned how long I plan to use it for. It is for the working day. It will be in the sun for 8 hours and I will be using my laptop for between 6-8 hours.

It is more about the project of designing and building than just buying a new computer. I will eventually buy a new computer but I would like to design a home solar station if this is a success!!

Thanks again.

[SunEagle]

Hi,

thanks for your quick reply.

Sorry I should have mentioned how long I plan to use it for. It is for the working day. It will be in the sun for 8 hours and I will be using my laptop for between 6-8 hours.

It is more about the project of designing and building than just buying a new computer. I will eventually buy a new computer but I would like to design a home solar station if this is a success!!

Thanks again.

Unfortunately a solar charging station for a laptop would be very costly and big to carry around. Most of the reason is that you really do not have 8 hours of useful sun (more like 4 to 5 in the Summer) and it will require a panel(s) with a lot of wattage pointed directly at the sun.

That portable 14 watt trickle charger that PNjunction mentioned would be helpful but will barely get a laptop battery charged back up to 100% even in a couple of days.

You would need a panel at least 100 watts and either find a DC-DC converter to get the correct 19VDC to your computer or use that pv panel to charge another battery and then use a DC-AC inverter..

[PNjunction]

The Anker 14w panel is a 5v usb output. OK for charging small Li-ion tablet, cellphone, external packs and the like.

But yes, a real laptop no way even if it was a nominal 12v panel.

Laptops are hard to predict since the owner will want to activate all power saving features, in addition to NOT always recharging their own oem batteries.

Calumbo - the best thing you can do for the environment is to keep reading.

If you feel the need to go further, you'll want to get some gear like a P3 Kill A Watt meter to measure the actual power draw while using power saving functions of the laptop in addition to charging / not charging it's own battery.

In all reality this is a toy application if you are just going to flush spare change down the toilet.

Meet us half way with your own legwork with the kill a watt meter and some more reading.

[Sunking]

Buy an extra laptop battery. Solar is not for your application.

[calumbo]

Thanks very much to each and every one of you. After reading a lot more,listening to you guys and talking about the idea out loud, it is clear to see that it would be silly to make such a thing. Thanks so much for your time.

[Sunking]

Thanks very much to each and every one of you. After reading a lot more,listening to you guys and talking about the idea out loud, it is clear to see that it would be silly to make such a thing. Thanks so much for your time.

You are welcome. FWIW you are one of the smarter visitors. You actually listened, did some research, gathered facts, and made an informed decision. Good for you. Not many will do that.

One tip buy a 12 volt power brick to charge your laptop from you vehicle. You do not even have to run the engine. Just recharge when you eat lunch.

[SunEagle]

Thanks very much to each and every one of you. After reading a lot more,listening to you guys and talking about the idea out loud, it is clear to see that it would be silly to make such a thing. Thanks so much for your time.

You can build a portable solar charging system but it will still be heavy to lug around and cost more than a few hundred.

I built one to take to the field when I flew my RC planes. It was a cool idea but not necessarily money well spent.

It has an 80 watt panel, 12v 65Ah batt & 200 watt inverter. ~$550 total.

[calumbo]

Cheers Sunking.

SunEagle that looks like an impressive build, but it would need to be carried on my back and carried up ladders. I must admit defeat and move onto another project.

Thanks.

[PNjunction]

You can build a portable solar charging system but it will still be heavy to lug around and cost more than a few hundred. I built one to take to the field when I flew my RC planes. It was a cool idea but not necessarily money well spent. It has an 80 watt panel, 12v 65Ah batt & 200 watt inverter. ~$550 total.

If it is gathering dust, then just imagine being able to ditch the weight, and the dolley for a 40ah LFP battery. (Covered extensively elsewhere!) Let's see, Pb 65ah to 50% DOD = 32.5ah usable. LFP 40ah to 80% DOD = 32ah usable. (also not that I advise going to 80% DOD on a normal basis when you take into account autonomy etc, but threw it out like the LFP salesman do....)

Makes a great stocking stuffer for the entire family!

[SunEagle]

If it is gathering dust, then just imagine being able to ditch the weight, and the dolley for a 40ah LFP battery. (Covered extensively elsewhere!) Let's see, Pb 65ah to 50% DOD = 32.5ah usable. LFP 40ah to 80% DOD = 32ah usable. (also not that I advise going to 80% DOD on a normal basis when you take into account autonomy etc, but threw it out like the LFP salesman do....)

Makes a great stocking stuffer for the entire family!

There is no question that converting from FLA to LFP would not only reduce the system weight but have a higher power yield.

But as I said before the system is "not money well spent" since I have used the complete system maybe 3 times over the last 2 years. The battery and inverter has been used a few times more but I did not include the solar panel due to the lack of sun for recharging. It is still a nice system to play around with but the $ /use ratio is pretty poor.

[PNjunction]

Very true about your usage - but at least with an LFP "learner" bank, the hands-on knowledge would be worth far more than the system itself should you ever want to go down that road in the future.

We'll leave that to the LFP subforum ..