Finished product is a 14.8 V battery at 8800+ miliamps approximately capacity that will run you for only about ? dollars. Here is how I did it.
Before you build this you need to be very careful and responsible for all your actions. I am sharing a how I did it, but I am not an expert.
Things you will need:
1. Soldering iron, solder, soldering holding devices.
2. Pliers, cutting tools, wire stripers
3. Electric tape
5. Lipo Charger
Materials and their cost:
1. Your macbook adapter(Free, since you can still use it after conversion)
2. Laptop batteries you will need to get 12-20 cells from laptop batteries - 15$+
3. Extension cable from adapter will be consumed.(assuming you already have it, other wise get a coil of wires for 5 bucks at awl mart and this project should consume less than 1/10 of that coil. - 50cents
4. A roll a electric tape 57 cents.(I prefer to buy a whole sleeve at home depot for about 5.70, and this will use close to a roll. - 57cents.
5. A roll of double sided foam mounting tape - 1$(Optional)
6. Cut off button - 1$ (optional)
7. Voltage warning device - 1.5$(optional)
8. CCTV male and female plugs 1$(buy 2 sets if you want to keep using your adapter)
9. Balance cable -1$
10. 2 strip ties - 10 cents
11. 2 18 cube or 20 cube conduit boxes - 1$ at home depot.
12. Heat shrinks(optional)
So, adding up the must haves Batteries 15$ + tape 57 cents + CCTV plugs 1$ + balance cord 1$ + strip ties 10 cents + conduit boxes 1$ + 30 cents worth of wires
So if we really went cheap on this, 19$ of materials will do the trick.
I will try to write this one precise.
Step 1: Pick the Right Battery Cells
Step 2: Solder Batteries in Groups.
Step 3: Assmble Half at a Time.
Tape or heat shrink and then fold to complete half.
Step 4: Solder Harness and Fuse
Solder a detachable connection to your final output. First strip some extension cable carefully, solder male dc plug to white and grey wires in extension cord, white to red and grey to black. Solder female plug to the none power bearing adapter, in this case the mag safe connector or a cig lighter socket.
Feed the wire into one corner port of conduit box. Solder a fuse holder or a weakest link I call a cheapo fuse to the positive, and hold wire in position with some adhesive.
Step 5: Final Assembly
If no spark and all is working, taking your voltmeter to test the voltage between the two groups, should be 14.8+or-.
solder those connections together and be good to go.