I made this new modular battery pack design so you can “safely” travel by air and be in compliance with the 99WH lithium restriction. Able to be completely disassembled and takes up hardly anymore room than a solid welded pack. I’m selling this one so I can build a similar 12S4-5P and incorporate a BMS. This one has no BMS because it’s only 6S, just balance charge with any lipo balance charger. The details of the pack are as follows:
Each module is 10 LG HE2 cells in 2S5P, 30 cells in total
2S5P = 7.2V * 12.5A = 90 WH per module, 270 WH total
100A continuous discharge
Includes two VGA harness, one board side, one charger side
Welded with 3 layers of nickel strip + 1/4" copper braid
Dimensions: 12" L x 3" W x 1.5" H
I also had to settle for wrapping the packs in 3M Super 33+ electrical tape because I couldn’t get PVC heat shrink to cooperate. Should be fine though, the tape is good up to 220 degrees F. Bullet connections are super strong, I swear the nickel would break off the batteries before the bullet connectors break from the copper braiding.
@Smorto What specifically would you like to know? I don’t have a motor or ESC that would work well for a 6S setup, so I can’t really set it up myself. The trickiest part was obviously the 5.5mm bullet connectors which took some trial and error. I welded the nickel and put some solder in the gaps between cells to hold the copper braid. I made sure to solder the bullet connectors to the braiding BEFORE soldering to the nickel (it took a lot of heat and time). Be liberal with flux, it is crucial for a strong bond. Then once the bullets were solid and in position solder the braid to the nickel (with flux!). Braid to nickel connection should be quick (less than 10 seconds). The cells didn’t even get warm since I had so many layers of nickel.
Awesome, thanks for the info. Would you happen to have a digram for your setup? Or perhaps just a few more pictures like the last one from the other side and other angles and such.
I am also wondering these questions but I would like to ask another one of @TheImmortalJew. I am trying to decide between with either this flight safe pack, or this one. I wouldn’t use your 6s5p though, I would change it to a 10s4p. Which do you recommend?
Sorry for the late reply. Unfortunately I don’t have any more pictures than what I posted before I wrapped it up. I used 5.5mm bullets, you should be ok with 4mm though. As for soldering the braid, I soaked the whole thing in solder first and put extra underneath where the connector is going to go. Flux it, then fuse the connector and braid together.
@Smorto I just hate XT connectors. In that pack, the XT plugs take up more room, I think they pull apart harder, and they need wire to go from cell to connector. However it is flexible if you need that feature. Mine is less flexible but way more compact since the cell are basically touching when connected and you don’t need wires.
Ok, thanks for the reply. Could I trouble you to possibly make a diagram for your current setup? It looks like you have 2 groups of 5 cells in parallel in each of the 3 detachable groups. Then once you take 2 of those 5 cel groups and put them in series with diagonal nickel strips like the outside ones in your 2nd picture right? You only used copper braid on the parallel connections right? Not on the series connection on the other side? I could easily do the same setup but modify it to be a 10s4p setup right? Sorry if my explanation isn’t clear.
