Powering Your Laptops in the field...

Here is something I've been working on for awhile, it's a document I created to help people come up with backpack-portable power solutions when SHTF or even expeditions or camping. I do alot of "field astronomy" sometimes so it's helped me keep things going for weeks at a time.

I hope this helps someone.

power-shtf-backpack.pdf

ETA: It is an ongoing project so if you find something wrong, I'll probably fix it (and update it) soon...

 

Very interesting to say the least, have you actually tested this in the field yet?

 

Yes, of course I have.. I've been doing this for a long time, and I've been using this all the time with the T23 and about a month with the CF-28... it works very well (but I live in New Mexico so I get alot of sun)...I wrote this article about 2 months ago, minor edits since.

 

if only we up here in MI could find a way to power our 'books with cold, lousy weather and SNOW

 

Thanks Terminus!

I knew you must be in my neck of the woods. Im in New Mexico doing archaeological work. Ive been looking for other power options in the field.

 

Good info. I've been looking for something EXACTLY like this that has been proven in the field! Great work!

 

Dewed - that is one frell of a good primer on backpackable power. I am impressed with the detail of your workup!

One thing to keep in mind is that the connectors you refer to as "Anderson PowerPole" are in fact generically known as Sermos connectors; they were originally designed for aerospace as a stackable high current modular connection system with low internal resistance and good wear characteristics. The guys at Anderson saw RC car racers using them in the 90s and started ordering them in bulk for resale, and the rest is RC history. A quick Google indicates that now they are nearly interchangeable terms; however when I was still racing I bought the generic Sermos connectors in bulk for about a quarter what Anderson wanted for the same thing; and they ONLY sold them in pairs. I dunno what they run now... An interesting side note is that they are quite scaleable; they make versions from 30A up to 300A (that I have seen used on wreckers to make a plug-in for jumper cables), and by parallelling multiple sets you can make the smaller ones carry much more current.

mnem
Photon...Electron... what-it-tron?

 

Great write up, T

I had been looking into something similar after seeing this site

http://www.rain.org/~philfear/how2solar.html

Do you know what the tradeoffs might be (other than weight) between the batteries you use and the marine deep cycles used on this one?

 

Hi...thank you!

In terms of other issues, no, I don't see any trade-offs. I wanted a backpack portable system, but definitely you should use as much solar panels and batteries as you can get your hands on for alternative energy systems. I live off the grid in the mountains and I'm slowly building my capability up. I have almost 1500w in solar panels, (2) wind generators (600w), and several kinds of batteries. Since I have several buildings spread apart by alot of distance up here I opted to go with seperate solar systems for each building. I use a fork lift battery (re-strapped for 12vdc) that I bought from a junk dealer, I expect to get another 15-20 years from that one, with seperate charge controller connected to (1) 600w windgen and 800w of solar panels for my living quarters, and a set of telco batteries (2vdc each) and a seperate charge controller for the observatory, that has 750w of solar and (1) 600w windgen attached. I use a VSAT for internet connectivity (Hughes Net) with a .98m dish, as there is no hard lines up here. I move around the state alot and my fiancee lives in the city so I often work from her place too. For vehicle-mounted systems, if you can afford the weight get golf cart batteries rather than marine deep-cycle batteries, they last longer. I only use Xantrex charge controllers for permanent installations, but honestly it doesn't matter alot what brand you use if you have backup units.

ETA: WHen I was referring to vehicle-mounted systems I mean like an aux. power system in your vehicles, someone asked me to clarify that. I like golf cart batteries because they can be cycled deeper and more often than marine deep-cycle batteries.

 

Very well done article. Makes me think a lot more about solar power and disaster preparedness. I wish I was more of a tinkerer.

 

Thank you! Whatever we think of what's going on today, we all need to be ready for disaster. Folks who live in the city need to be extra prepared if you ask me. We're living in interesting times.

 

Thats a very helpful and very useful document, thank you for sharing it.

 

Thanks! You're very welcome! I'm sorry that we couldn't work out something on that other thing. I hope to help others with anything I can to keep the spirit of this place alive and growing.

 

thats an excellent idea, but you forgot one thing

please tell me where you get that excellent looking solar pannel

 

It is a Global Solar 55 watt panel, you can get them from EBAY I suppose. I think they have a web site but I don't think they sell to end users. The civilian models are marketed under "SunLinq" brand (same company afaik) I have seen Global Solar products being sold at Brigade Quartermasters (i think it's called actiongear.com)

Thanks!

 

You can try cheaperthandirt.com. They have them. Not sure if its the same exact one, but they get stuff all the time. Kind of like ebay, you have to keep checking to get what you want. They are mostly military surplus I think.

 

If you want to try experimenting with solar panels, but aren't sure if you want to go for the full treatment yet, there are surplus panels at places like www.surplusshed.com (lke what Edmunds Scientific used to be).

 

It's also fun to buy the cells in bulk and build your own 50+ watt panels. I did that a few times but always have issues with the frame I made. I also hope to (someday soon) buy a bunch of the flexible cells and build my own flexible (roll-up/fold up) panels. You can get them on ebay once in awhile, and they can even be purchased pre-waterproofed for a bit more. (I have the links somewhere in my favorites if you need it)... Otherwise you'll need to seal them somehow with a UV friendly coating or sheet that is also flexible. Then you'd just need to have some decent sewing skills. Believe it or not, I learned to use a sewing awl just so I could do that someday. Until then I've only repaired backpacks and other gear. I've never done leather though

 

Leather is not too bad to work with. Ive done leather clothing, a few larger bags and lots of archery gear. Golf cart batteries? Wow I would never have guessed...I will look into that. I use marine batteries in my Yurt, off grid, in Washington's Olympic Peninsula. My set up in not nearly what you have but it gets me by when Im there..lighting, computer, and communications.

 

Terminus... Can I ask what you paid for that 55W solar panel?

 

Hi TB, I bought it used for $500, I paid alot (too much) at the time, they were selling for alot more. I believe you can get the civilian version for less than that new now.

I.E. The one I bought was market as GlobalSolar but they're selling the same one (albeit black) as SunLinq...

 

That was an awesome write up!! 'm impressed with how clean and simple all of your was. I downloaded it for future reference.

Thanks

 

I figure I would bump this excellent thread by Terminus back up to the top since we have some new members.... And since I am thinking about doing the same thing. There is a 30 watt foldable solar cell setup on ebay for under $300 and I was thinking about starting there... I am waiting on the seller to get back to me with a few answers first though.

Everyone should download terminus' beautiful PDF if for no other reason than to be prepared. It is very well written and explains pretty much everything you would need to know about powering your Toughbook (or any laptop or like elec. gear) with a solar cell and a few other items.

Enjoy!

 

I saw a solar charger at Walmart the other day, made by Black and Decker I believe. It is a pad about the size of a small pizza box. Looks like it would work as well some how.

 

LOL - Well, sure - if you only wanted to power a calculator, it would be fine. A modern laptop requires about a hundred times the current that puts out; hence, the larger panels we're talking about.

mnem
WalMart sucks. Ask RainMan.

 

I think you would be suprised there buddy. The battery, solar and how to obtain and how to hold that power is changing everyday. The biggest advancement in the next year is going to be in batteries. Every major player is working 24/7 to find the answer for getting power from it.

Here are the specs for it. I feel its not too shabby for the Sun's power.

Product Specifications
AC output power (continuous) 320 W
AC output power (2 minutes) 400 W
AC output surge capacity (peak) 600 W
AC output voltage 120 +/- 10 Vac rms
AC output frequency 60 Hz +/- 1 Hz
AC output waveform Modified sine wave
Internal battery capacity 10 Ah
Inverter no-load current < 0.4 Adc
DC output 12 Vdc
USB output 0.5 A
AC charger specifications 500 mA

General Specifications
Dimensions (L x W x H) 15 x 4.5 x 10.25” (38 x 11.5 x 26 cm)
Weight 12.3 lb (5.6 kg)
Warranty Six months
Regulatory approval cETLus

Packaging Specifications
Part # 852-2071
UPC 7 15535 11455 8
Gift Pack
Units per package 1
Dimensions (L x W x H) 17 x 8.5 x 12.5” (43.1 x 21.5 x 31.7cm)
Weight 16.1 lb (7.3 kg)
Master Carton
Units per package 1
Dimensions (L x W x H) 17.5 x 9 x 13” (44.4 x 22.8 x 33 cm)
Weight 17.6 lb (9.8 kg)

 

Ummm... what you're talking about there is an AC inverter connected to a battery, not a solar panel. What we're talking about in this thread is solar panels; particularly ones large enough to run & charge the batteries on a laptop in the field. Actually, out in A FIELD... or a desert... or anywhere else you don't have any form of electricity but what you bring yourself.

Sure you can charge the 10AH battery in that power pack from a small solar panel; but to get it to full charge will take days, during which you cannot use your electrical goodies. In order to actually be able to USE your stuff AND charge the batteries (for use at night or when there isn't adequate sunlight) you need a much larger panel than "a small pizza box". I have several such small panels; here in TEXAS, they're GREAT for keeping your car battery topped off on vehicles you don't drive often but they won't provide enough current to run anything hungrier than a CPU cooler fan.

Also, if you look deeper into the thread, you'll see a lot of talk about specific DC-DC power adapters for specific laptops; this is because using an AC inverter like the one you suggest and plugging your regular AC adapter into it to charge/run a laptop is dreadfully inefficient; you have loss from two inverter circuits and two regulation circuits, where with the DC-DC car adapter you have loss only from one such circuit. :GEEK:

So yeah, we know about solar here... we get right into the nuts & bolts of it. :wink:

mnem <~~~ Rabid TinkerDwagon & Putterer-About-Town*

 

Hi,

I somehow missed this download and the link is no longer working. Does anyone have it? It is very relavent for me just now.

Thanks!

 

Yes. Give me your email addy and I will get it on over to you.

~Paul

 

Link works for me. Opens right up in Adobe Acrobat Reader and allows me to save a copy (which I did). Thanks Terminus.

 

Link works for me too, the .pdf saved fine, opens in Foxit Reader no problem.

And of course there's the ever-popular kerosene radio... I imagine a kerosene Toughbook would probably be a bit harder to pull off, though.

 

I almost wonder if some sort of bicycle generator would be feasible. Maybe even more practical than a solar cell. Of course, my arms would get tired after a couple hours of that.

 

Yes, it would be very difficult. I worked as a service technician for a local gas utility before I moved into the IT department. Almost all gas fireplaces in use today utilize a thermopile setup that is similar to the ones used in the kerosene radio. The thermopile is heated by the pilot light to generate the power to operate the main gas valve. This is why they work even in a power outage.

The problem is that while they generate ~1/2 volt DC, they have almost no amperage. They also take a pretty decent sized flame to generate even 1/2 volt. The number of thermopiles you would need would equal a sizeable amount of fuel. Probably better to use a fuel cell technology if you are looking for hydrocarbon based off-the-grid alternatives.

 

Where I lived in Sydney for the last 10 years reminded me of this - power outages are very common since the redundant main feed into the town was reduced to single power feed and the area being high up is affected by summer thunderstorms so that compounds the problems. A few years ago a lightning strike hit nearby and took out a bit of my comms gear and fried ethernet ports in some of my Sun servers and workstations. The emi from the lightning seems to have been picked up in the long ethernet cabling running through the house and only the gear on the longest cables running between different ends of the house was affected.

Now I have good quality UPS's running everything there to manage the power outage side of things, but proper lightning protection is very expensive and with mortgage + family so it's not really affordable though always in the back of my mind as I have wanted to set up a local wireless network for a few years and if I did any type of radio-related data comms that would definitely have to use full lightning and surge protection.

Here in Adelaide the aging electricity infrastructure suffers differently. There are very small power stations and two larger ones (all gas-turbine stations except for one which is coal-fired) and last week there were 'structured' blackouts to cope with excess demand on 45 C plus temp days. This city has no electric passenger trains (yet) and public transport is fairly poor so I hate to think what would happen if the government had an electric suburban train network with very high power demands competing with the other domestic/industrial power users for supply! It raises a lot of interesting questions about how failover to portable systems is set up, so those of us with toughbooks are going to be in a better position than most.

I have a Lind power device to run my CF-28 in the car (which I plan to use with a Ledco docking station), but the same sort of setup can be used to run a toughbook on DC power just about anywhere. A lot of people not on grid supply run various AC and DC power systems and plenty of people I know use DC exclusively because it fits better with their solar setups. That's the other thing - solar is expensive...

One thing I would like to do it try out a few solar panels on the roof of my car secured horizontally between the roof bars and see how I can configure them to charge a good quality battery like an Odyssey PC925 and use that set up to run the toughbook in the car so it doesn't run of the main battery (which is only going to work for a limited time when the engine is off, and that compromises the starting ability).

I don't know if I'd want to take a CF-28 in a backpack-style situation but it's certainly rugged enough. The issue of weight of external power support gear then becomes an important issue too (something which the military people among us probably have experience with).

Craig.

 

Doobi, thanks. The link is now working, go figure. Thanks for the offer.I saved it this time.

 

I like to bring this thread up from time to time. I am still shopping for a large folding solar panel. (I can trade parts if anyone has one they want to part with! )

But the link is still good for the PDF file.

Terminus did a great job on the write-up but I don't thinkhe drops by much anymore.

 

great write up indeed! very interesting

 

Terminus lives out in the desert off the grid... So he should know!

 

I'm wondering if there's someone doing this with Lithium-Ion and (of course) a corresponding charger.

We use batteries like these in my line of work ( http://www.antonbauer.com/Products/Dionic160) .... Anton Bauer Dionic, 160 watts at 14.4v. It's expensive but it's a beast to power the power-hungry cameras we have today. Which is why it's important to buy LithiumIon cells designed for high-draw as those that are not, you'll kill them pretty quickly.

Camera - 40w (up to 70w surge when the laser turns on)
Viewfinder and lens, wireless mic receivers - 10w
HD wireless transmitter - 30w
Camera light - 20-50w

 

I have done it with Li-ion batteries from Ryobi cordless drills a few times, you need to hack apart the charger and mount a dc-dc converter just upstream from the AC transformer and Recectifier. when Im back home next week I can dismantle one and take a few pictures of my setup.

If your handy tracing your power lines in an AC charger find the point where it has run your DC voltage to the charge circuit you can splice in appropriate power there

or to make it simple build or buy a LI-ion charge controller and mount it between the charge circuit and the battery

 

Whoa.... dewed... just to keep up with that load, you're going to need a 200W panel; 2 of them if you want to actually be able to charge up in a reasonable amount of time or charge while using your equipment. 200W @28V IS a standard "e-module" solar panel size (approx 65" x 39") ; but standard panels are NOT designed for "portable" use, they are pretty fragile. Add to this the cost - around $650 for economy models, all the way up to $1800 for name brand panels with high-efficiency cells that still generate full or nearly full power even when the light is coming in at an oblique angle... and MAN, you are TALKING SOME BUX, cuz then you need to add a solar charge controller.

Terminus' setup uses a 55W panel that measures about 6' x 8'; and as is typical for most USEABLE solar systems, his total system load averages about 20-25W with occasional short-term usage in the 30-35W range. To keep in that same 40-50% loading range, you would need 4 or 5 of the flexible solar panels he used, and enough room to hang them!

I understand that you run on the batteries; but remember, in order to charge at the same rate as you are using, you need approx 125-150% as much solar capacity as the load because your charge controller and your power conversion gear are not 100% efficient. This means that if your system draws 40W for 6 hours to deplete your battery, you need to charge at a 50-60W rate for 6 hours to fully recharge - more if your panel is not at optimal angle or there is cloud cover, etc. If you want to charge in less time, you need even more capacity - if you want to charge in 3 hours for that same 40W system, now you need 100-120W (probably more in the real world) capacity.

Remember that these figures are not actual numbers to calculate Volts at Amps and add up the cells in a panel for final system engineering; they are just thumbnail estimates expressed in the simplest common terms to give you a place to start from.

mnem
E=MC^2... most of the time.

 

very good workup on this ...been thinking i could use something potable like this on my hiking trips...kudos man

 

Another plug for this thread for the newbs.... Great info. I like to bring this thread up every now and then.... This time as someone asked specifically for something like this.

I hope Terminus is doing well wherever he is..... I hope the rattlesnakes didn't get him!

 

I am interested in making an external battery pack for my CF28. The AC adapter say's it's voltage output is 15.6v, @3.85A.

Question: What are the minimum and maximum voltage that the CF28 will accept before I see the magic smoke?

Question: Does AC adapter have a voltage regulator?

Question: Will it boot without a battery as long as the AC is plugged in?
(It doesn't seem to make much sense to plug in a fully charged external battery only to loose efficiency as the onboard battery tries to charge at the same time...)

 

TB you heard me, Thanks for this Terminus!

It answers most of my questions for portable solar power for my CF-29.

 

HJ,
I dont know about the CF-29 input voltage limits, but I can tell you the way I use my Tekkeon external batteries with a CF-M34 MK7:
As Tekkeon bat output can be set to different voltage, I set the output to 14V (normaly, CF-M34 requires 15.1 to 16V input), and plug it in the CF-M34.
What happens ? First, the external battery is drained, and when it's empty, the computer starts using the internal.
This way, with my 2 // Tekkeon (3450+3440) connected and a good internal battery, I ran the computer (bright screen and working) over 12 hours to test it.
Small screens suck less power and more generaly, if you want to use a computer on solar, the FIRST thing is to have a computer that doesnt use much energy. Probably, you can set a power profile on the CF-29 that saves battery live (CPU usage, screen brightness, disabling wireless (if not needed), etc...

I forgot something in my description, at 14V, the internal battery doesnt charge, but the computer uses the external power.

 

Heh -

The rattlesnake that bites Terminus? It's gonna curl up & die, not HIM.



mnem
Tree good. Fire BAD. I think...

 

Well, that is a fine thing to know!

I'm curious to know how low it can go. I wonder if a cigarette lighter hack could do the trick, sans voltage regulator? Sounds like a worthwhile experiment. An automotive charging system can go as high as 15.6v, but with the engine off, 12.8 is the usual. I'm not inclined to backpack with my Toughbook, but camping and caravan is a different story.
I have a couple of 75w panels on top of my camper to keep me in juice for radios/etc. If this could be done without an inverter or buck-boost circuit, it would be a lot more efficient. The panels put out 17v, so it's almost a perfect match in and of itself. Maybe dropping diode or two...

 

One option that might be a consideration is using the Lind dc/dc adapter
The lind 12 volt car adapter is quite flexable for power input and will always output the proper output for your Toughbook if the input power is within specs (12 to 32vdc)


Alex

 

Yup... I agree.... That guy can squeeze water from dirt with scrambled eggs on the side. I still hope he posts... I haven't seen or heard from him in a long time. He used to call me on a somewhat regular basis... He must be WAY out in the desert!