Updated: 5/2/06: Each Milwaukee pack contains 7 cells of ~3000 mah capacity, each weighing about 100 grams. In order to transform the pack as it comes from Milwaukee into a usable flight pack, you need to extract the cells and build up a pack to fit your space requirements. The disassembly procedure is fairly simple, but some people have been looking for a roadmap to take them through the process. I've built several packs already, and since I was going to build up a couple more, I thought I'd take some pics along the way. Note that this is the procedure that I used and I'm sure there are other methods that could be used also. At the end of the document are wiring diagram for TP210 Balancer. 5 Cell, 6 Cell and 7 Cell diagrams. (Thanks to Kookboy and Gary Goodrum!) Disclaimer: What I am showing here is the procedure that I used to remove the cells from a Milwaukee pack and reconfigure them into a flight pack. I am not suggesting or encouraging anyone to follow this example. I believe that it is always a smart idea to protect your eyes with safety glasses or goggles when working with battery packs, as the possibility always exits for something to go wrong. Good luck, Lenny (Lenny970 @ rcgroups) Additional Contributions: Hoverup, Gary Goodrum, Captain Carlton, Ozace, Lift, cgbole, Kookboy, and many others too! Size and Dimensions: One Emoli Cell = 26.52mm Dia. X 69.47mm Long and 98.7grams with the cardboard sleeve.
I start by removing the 5 screws holding the case sides together. A knife is used to cut through the lable on the bottom of the case. Now the case sides can be pulled apart. A little prying and pulling and they open right up. Here's what you'll find inside. The battery pack is not fastened to the case, so once the 3 parts of the case are pulled apart the pack is out.
The arrows show where I cut the power leads to remove the electronics module that is not needed. I just pulled the small wiring harnes (tan colored wrapping) around the pack to remove it. The blue stuff here is memory foam that is stuck around the pack. I like to remove it with a screwdriver blade to be able to better see what's going on. Once the foam has been removed, you can clearly see the metal straps that join the cells. To better handle the current requirements of flying a model, the spot welded, thin straps will be replaced with heavier bars soldered to the cells. I first remove the two straps where the original power leads were connected. The straps joining adjacent cells are next. I slip an exacto knife under the strap to raise it up just slightly. The straps run over the top of the black plastic cell holder, so the knife goes between the metal straps and the plastic holder.
After the center of the metal strap has been raised slightly, a screwdriver blade can be inserted. With a twist of the blade, one side of the strap will pull loose from the spot welds. Then, the other side of the strap can be pulled off the other cell just as before. A "rolling" motion with the pliers easily removes the strap, like peeling a banana. Once all the straps have been removed, the plastic cell holders are removed from each side and the cells are now loose. Here they are! Raw cells ready to be built into a new pack.
I use a Dremel with a sanding disk to rough up the cell ends a bit and remove any remnants of the spot welds. Tools of the trade for building up the pack. I like the battery bars for making a side-by-side pack, though heavy stranded or solid wire would work fine too for joining the cells. Here the cells have been joined with battery bars and the power lead has been added. I like to use a bit of Goop between the cells to give the pack some extra structural strength The finished pack complete with heatshrink and velcro. I didn't include any balancing leads here, but I can go back and add them later if needed.
Here's a shot of the finished pack from the other side. This pack is for my Swift. 5 Cell Emoli Flat Pack, with TP Taps. FAQ: Where do you get the Battery Bars? From many battery suppliers. Battlepacks, Cheapbatterypacks, AC World, etc. Not everyone is using the bars. Some folks are leaving the original connectors between the cells. Both groups are reporting good results. Using replacement bars most likely reduces some resistance, and allows you to suck a bit more juice out of these batteries. How do you charge these? Just like a Lipo Pack, 1C or 2C, no problem. Discharge maximum is around 15C. How far can I discharge these? People are saying that you can deeply discharge these battery without damaging them, unlike current Lipo batteries. Not sure I want to personally risk this until confirmed. What kind of Covering should I use? Generally 5 Mil heat shrink is good! If you are making a flat pack, like the one above and to the right, then www.batterysapce.com sells PVC: 5 inch (126mm)Width Shrink Wrap for DIY Battery Packs PVC-126BK How do I Solder Balance Tap on these Packs? Pretty Easy. We have included diagram on how to solder the connectors if you are using Thunder Power Balancers. Buy the balancer plugs (aka taps ) online from a vendor such as www.tppacks.com or www.atlantahobby.com. Check out the next several pages of this PDF. What if I fly too long and I run out of Power? I can tell you from personal experience that these packs dump fast when they run out of juice. It is not a gradual let down as the power drops quick. If your in a helo, you looking at a definite low RPM situation, so a Power On Auto may be needed.
Thunder Power 210 wiring diagram for 6 S Pack. You ll need one 6 pin and one 4 pin, just like the 7S Emoli diagram. Thanks to Kookboy!