Did they tell you at all the reasons for the re-wrap? or they admitted cells are fake? More details bro.
They apologized, and said they’d contact their supplier for those cells. They said if they get an update from that supplier, they’ll let me know.
That’s all they said, apart from providing the label and saying I’d get a full refund when they receive the cells.
3 Likes
Any idea for how difficult it would be to take the nickel off of the cells and make a completely different pack? Gonna make an ebike battery if anything
1 Like
Peeling nickel off isn’t too bad. A pair of flush cutters and/or a dremel will take off the little nubs left over from the spot welds. Just be a bit careful not to go too deep with the dremel - you don’t want to take any material off the can itself, just dress down the bumps.
3 Likes
Following all of this is making me feel better about my second hand ancient Panasonic batteries 
2 Likes
Hello All!
I don’t even have a board yet, but here I am building a battery. Super interested in all the things! I bought a bunch of packs to harvest cells. Testing with XTAR Dragon and Opus BT-C3400. So far I am only keeping cells with low IR and those that had at least 2V when freed from their packs. Lots and lots of time involved with that which leaves me time to learn and 3D print stuff…
That said, I have looked at many pictures of @Winfly design and would really appreciate someone to confirm placement of BMS leads. I have provided pictures below.
This 2S3P pack is just for testing as the materials were super reasonable, price wise, to get started. The plan is to evaluate a few different methods and see what sticks. The cool thing is I can print these in 1 hour 15 minutes with a 0.6mm nozzle and layer height of 0.3mm in PETG.
My slicer is estimating a 10S4P pack to take about 6 hours to print which seems really good. I will try the N.E.S.E. version as well just for comparison in print time. There are a few other “solderless” methods I’ve seen on Endless Sphere that I will try as well, with magnets being the most intriguing. Anyway, great forum and thanks to everyone that has shared information and knowledge!
5 Likes
That looks a lot better than my first p-group 
3 Likes
Damn bummers hope you change that soon ;), but welcome to the community still
as long it’s all the same brand and model cells it should be good also make sure to have about the same capacity all over the p groups
the BMS leads goes where you pointed at, the most negative goes to the -, the first series goes on the + side of the same cells (or the - part of the next pack) and the most positive goes to the last + side of the battery
1 Like
Looking good so far dude
4 Likes
whats the green paper covering the cells I’ve used it in the past, cant find it on aliexpres thanks
1 Like
Fishpaper / transformer paper. Usually adhesive backed
1 Like
I just finished my battery using @Winfly design. Modified it a little as I made them out of Delrin on my CNC and added a set screw over each battery terminal. I’m curious how you’ll transition from the braided wire to a connector like and XT 90 / XT 60. I cut a small line into the terminals so the braided wire could lay flat and soldered it to them.
Oh, that sounds like a good idea! I would really like the main file @winfly used… to redesign them as I have some other ideas to try. For example, instead of a raised bump where the compression pushes the braid into the battery… I was thinking about adding a magnet recess. Stack would be:
[Plastic -> Magnet -> Braid -> Pos/Neg Battery]
There are guys running copper foil and magnets on Endless Sphere with great success. They cover the entire pack with plasti-dip and it looks bomb proof. I am using old/used cells and would like to make it easier to replace bad cells as they inevitably show their evil faces. Plasti-dip would make that significantly more difficult, in my mind at least.
I have been pondering this quite a bit. If you squeeze the braid together it folds into a “wire” quite easily. I measured 4.15mm in diameter (give or take) which is darn close to 12AWG (give or take). A few things I’ve been thinking about…
- XT30/60 connectors - Need to solder and may present some difficulty - cost $0.90 ea. (amazon)
- Deans connectors - Need to solder and may be easier than xt30 - cost $0.70 each
- Anderson connectors - Crimp - cost $1.50 each
- Deutsch connectors = $$$$$$
- 12 AWG Ring terminals - Crimp - cost $0.20 but you will need to secure them together somehow.
- 12 AWG Bullet connectors - Crimp - cost $0.76 but factor in price of crimping tool if you don’t have one
- permanently attaching packs together with solder? Cheapest solution - Not modular and seems very dangerous if you need to get into the pack.
I like the idea of multiple uses and I see value in simplicity. I have lots of xt30’s but I am liking the idea of 12AWG bullet connectors as it seems quicker, simpler and will have other uses. I can see lots of pigtails in my future if I use a dual connector for a single polarity, with my lack of knowledge in higher power setups that scares me a bit.
You’ll need to ensure your connectors can handle your amperage. I played it safe with XT90 but they do take up more space…
I’ve used winfly modules on two builds, I trim the braid to end inside the module and solder silicone wire to it through the end hole. It’s easier to trim the braid and solder pretty heavily while it’s out , then feed the wire through and assemble.
Good ideas! What gauge of wire are you using? How are you terminating the connection?
1 Like
