DISCLAIMER: These articles are the findings and opinions of one person. Long-term durability of these cells is not known for our application/construction techniques. Any cell technology that we use is potentially dangerous. Do not work with these cells if you do not have a healthy respect for them, or if you lack the requisite skills.

After you've dissected your DeWalt 36V pack, you can create a lot of pack configurations with minimal work. This article is to get you started. You can extend these concepts for your own applications. The first two pictures below define the cell ends as the basis for construction [trick] photos. The most negative cell is C1 and the most positive is C10. Don't forget that the case is positive and the button is negative!

Top View of DeWalt Pack

Bottom View of DeWalt Pack

The goal in making packs is to take advantage of the existing straps as much as possible. This minimizes labor and potential heat damage from soldering. Carefully cut straps where necessary using diagonal cutters or a razor saw. Always cover other terminals with masking tape to avoid undue excitement. We'll start with some simple "brick" configurations.

6-cell "Brick" Pack

4-cell "Brick" Pack

These packs can be covered with 5" (measured flat) shrink tubing. If you use a balancing connector, solder the leads to the connectors midway between the cells. Use a large tip to get the job done quickly. You can use tape to hold things together if you don't feel the shrink tubing adequate.
Now for some flat packs:

5-cell Flat Pack (bottom view)

5-cell Flat Pack (top view)

4-cell Flat Pack

Flat packs can be covered with 4" shrink tubing.
Next we'll "build a 5S2P pack. The best way, especially if you use balancing connectors, to implement parallel packs is to parallel all cells. This can be done with smaller wire, since there is only a small amount of current flow. You can use two positive (red) leads and two negative (black) leads and join them at the pack connectors.

5S2P Pack (bottom view)

5S2P Pack (top view)

Notice that we used a "battery bar" to make a connection. Alternatives include using a scrap of 14- or 12-gauge house wiring. Flatten it with a hammer. If you use 13-gauge high-strand-count wire for power, two of these should fit into a 10-gauge APP (Sermos) contact. If you don't plan on high current use, you can use a single power lead. In this case, use a battery bar between C3- and C8- and between C2+ and C7+. Like the bricks, A piece of 5" shrink tubing finishes things up. Next we'll make a big pack, an 8S2P: 8S2P Pack Only the top side wiring is shown. By now you should be able to figure out the other side. Last but not least, we'll do an end-to-end pack. We'll start with cells C5-C10, as with the 6S brick. We simply fold over the connections between cells. If you look at these straps, it's obvious that they're not going to want to bend "square". Use a hard piece of insulating material, such as a hardwood spar, to force the bend to be straight. This will form a good 90-degree bend. Then you can fold it over the rest of the way. If you're obsessive and want things as small as possible, you can squeeze the cells together with an insulated clamp. After unfolding, you can add balancing taps. I used a "rainbow" ribbon cable and a connector shell and female contacts I got from Digi-Key. Unfortunately, for some reason I used color code for 1 to 7 rather than 0 to 6. Not a biggie, but denoting negative as 0 and cells as 1 to 6 seems more logical. The pins are on 0.1" centers same as PolyQuest and others. These pins are more substantial than the 2 mm. pins on some others. When adding tap wires, it is important to insulate things as you go. Also, add one pin at a time. Don't add a pin until the previous pin is safely inserted into the shell. Note that I wrapped the pack in a doubled sheet of paper (rubber-banded) and taped each lead. I soldered the power wires to the end of the tabs. I probably should have done some strain relief with string, but I forgot. I decided instead to beef up the pack with strapping tape before adding shrink wrap. It looks pretty bad, but inside the plane, who cares? The next photo compares the final pack with my end-to-end soldered pack. Sure it looks bad and weighs almost an ounce more, but it was a lot easier to make, and there is no possibility of heat damage. Attaching balancing tap wires to an end-to-end soldered pack is also problematic. Still, the bottom pack sure is pretty!

The final picture shows the odd pack that I needed to replace the 2S 3200 LiPo pack in my Jim Ryan P-38. The shape was necessary to fit and give room for connecting. This pack took a grand total of a half-hour to make including the tap connector. I use the West Mountain Radio crimping tool for my APP connectors.