Lydian's FastMHz

Autie retro tech geek!

Mega External Laptop Battery Pack

My Toshiba S75D is an awesome machine, but the rather lacking battery life needs to be addressed, and this is an area where I excel 🙂

Recycled lithium batteries and a $6 DC-DC Boost convertor should provide plenty of power for my laptop.

Battery pack – 14.4v, 10.8ah (24 Li-Ion cells, 16.8v nominal voltage)
Low Battery Alarm – Blue LED = full, flashing blue = good, red = low, flashing red and beep = dead
USB Charge port – 5v, 3a
Output – 19v @ 6a (Max); Laptop draws 19v @ 4a fully loaded and charging
Charger – Solar -OR- Fast charge via Astro Flight Lithium Charger

The testing phase! According to my calculations, this power pack will run my laptop for ~10 hours under light load (not charging internal battery), or ~4 hours under 100% full CPU load (not charging). Then I have the ~3 hours in the internal battery. ~13 hours without access to an outlet is unbeatable!!

I decided that I wanted a USB charge port as well for phones and the like.

02-27-2014: I figured out that an 80CD wallet is the perfect size for all the components. I ordered a hard plastic one on eBay for $5 and will modify it for this project. Having a zippered enclosure makes it easy to open and charge with my Lithium charger. Knowing this, I did the wiring and a mockup installation in another 80CD case I had laying around. The final version will be much more refined, of course.

Here you can see how everything fits in there rather well.

Finished up the wiring, lots of heat shrink for professionalism and safety. I even heat-shrunk the USB charger board.

Wiring looking good…

Everything fits!!

03-04-2014: For the hell of it, I’ve decided that this battery needs to be able to charge itself:

Therefore I ordered two of these for less than $13 total which will give me 4w of charge power 😀

03-06-2014: Got the hard case and transferred the components from the temporary one. Once I get the solar panels, I’ll finish the project and post some more pics. The red color will be good when the device is sitting in the sun charging, as it won’t absorb as much heat.

The device can be seen here getting a charge.

03-17-2014: The solar panels finally arrived and I got to quick work installing them in my external battery pack.

First I wired them in series and soldered on wires to the tabs.

Then I scanned the actual panels and printed a life size template.

I taped the template to the case and using a utility knife and metal straight-edge, I cut out the hole as best as I could.

I don’t think I did too bad, really. Cutting plastic isn’t a particular specialty of mine…

Panels temporarily installed to get an idea of final result.

Next step is to install a diode and wire the panels to the battery bank. Next update should be of a completed project!

Got the diode and wires ready. The diode prevents the batteries from discharging into the panels in the dark.

Diode soldered in and tested for proper current flow.

Final product!!

There is really only one thing left to do and that is to make the USB charge port accessible from the outside. Right now, it must be partly unzipped to access it.