So my first eskate was an off road belt driven prebuilt called Outstorm. it was an okay board but the esc lacked the customization that the VESC offered. I immediately got to modding and dissecting. The battery design seems somewhat unique compared to other batteries I have seen online or disassembled myself. The original pack was a 10s 4p of LG M26? cells. Not bad. So I doubled that with M29 cells at 10s 8p.
Here is a 2s of the general design the Outstorm had which I have replicated in 8p
I like the uniformity and balance of this design so I took that cell orientation and added a few more ways to make my cell pack as “self balancing” as possible to ensure longevity. I don’t like how most builds have all power being fed across 1 or 2 cells between series connection. Those “bridge” cells are just about guaranteed to bring down the life of the whole pack, usuable capacity, and make the bms have to work.
With the “ultimate parallel design”… all cells work in unison. I also made the electrode wires balanced as well as you will see.
On the left is my original design and on the right is my updated design. I watched more build videos (Pavel mainly) and I got paranoid because I forgot insulation rings on positive electrodes (which I already had inventory), also used too thin .15 of nickel strip, and just didnt use enough tape…
So I got paranoid and ripped off all the nickel and tape to start over. SO glad I did. I used a cheap spot welder first time then I got a kweld… Do yourselves a flavor and get a kweld.
Plenty of power to provide structurally sound welds to .3mm pure nickel.
Anyway… So I got to taping and was more careful to isolate the balance leads. I used fish paper on the first go round and salvaged a good bit when I ripped that build apart… But I still ran out the second time. SOOOO I used kapton tape and gorilla tape. I love gorilla tape.
Below is the 5th and 6th series connections where the bend occurs. The “butt” of the battery you could call it because both electrodes are on the other side. I have plenty of kapton and gorilla tape in there to keep the series connections isolated.
Below is a balance connection. I soldered balance wires on then added kapton and gorilla tape over that.
Below is the “top” of the battery. a bit precarious to assemble since the positive and negative electrodes are adjacent to one another. But I put fishpaper, kapton and gorilla tape all in there to insulate.
Here is where my “self-balancing” electrode wire design is shown. The original outstorm battery had 1 12gauge wire connected to the cell closest to the outside. Obviously that cell is going to fail sooner than the other cells and kill the pack early. So I made sure that every cell would be equidistant from one another and the electrode wires. Here is version 1 with 12 gauge wires.
But I ripped this battery apart and on the second round I used 4 red 14 gauge wires instead to ensure each cell had equal access to the load.
I had no problems with my a few months of first design but didnt want a catastrophe. As I had developed 3 solid ways to improve the battery I went ahead and ripped it apart.
I have such a large battery that I am able to run my cells at 80% capacity or so while still being able to get distances of 25-30 miles. I typically shoot for 4.0v per cell when charging and have my vesc set to cuttoff completely at 3.2v
So if all goes as it should I will get 5+years out of this pack even with daily use. Also my 10s 8p LG m29 pack can do 80amp continuous but I have the Vesc governed to 40 amps max and I have never once maxed out my throttle. The battery isnt even warm when I get done riding.
Thoughts?
Concerns?
Tips?
This is my first 2nd? major eskate battery build. I have done other small packs before. But as we know eskate batteries are just a different animal with all of the constraints we have to overcome.
Thank you for your interest.
