First go on the internets and buy some LiFe cells. I specified LiFe cells because those are the ones that I used. You can buy some directly from the A123 website. I used A123 lithium ion cells for my battery packs. They carry 3.3v nominally and 2.2aH. Use a voltmeter to make sure that the voltage across every cell is 3.29v-3.30v. Make sure that all of your battery cells are at the same voltage. Your battery pack is as strong as its weakest cell so if some of your cells have 3.29v and others have 3.3v your battery pack will die when the 3.29v cells die, regardless of whether or not your other cells still have charge.
|So many batteries!|
|Two cells in parallel|
|two pairs in parallel|
|small packs of 2s2p|
Now begin gluing the pairs to each other and make sure that their terminals are facing away from each other. This is because we are about to connect the pairs in series. We wil use copper braids to make this connection; I'll explain it later in the tutorial.
|Two 5s2p packs;|
|Positive, negative, positive, negative, positive...|
|Use sandpaper to clean up the terminals|
|Notice the first pair of batteries have two negative terminals connected with copper braid. This is the pack's main negative terminal.|
|Note the thin cables connecting the parallel nodes together.|
|Finally finished soldering two packs.|
|Balance connector housing|
|XH Crimp Connector|
|If you don't have a crimping tool you can just solder the wire onto the crimp connector|
|Make sure you connect the red wire on the arrow|
|Balance wires and main positive/negative wires complete.|
|Heat shrink the battery pack|
Anyway, I hope my tutorial was helpful! Good luck!