Can these be drilled and tapped?

[MurphyGuy]

Does anyone know how deep the material is between the aluminum tab and the top of the lithium phosphate cell inside?

Can these be drilled and tapped? I can't tell how thick that aluminum piece is or if there's anything under it that the drill could run into and damage. Obviously, practicing depth control will be important, but precision on a process like that can be difficult if the material is just too thin. Is there even enough material to tap a small machine screw thread? #8-32 or #10-32 ?

I'm thinking of bolting copper buss bars to these tabs using a set of stainless steel machine screws. Maybe 4x 10-32 screws going into each tab should provide adequate mating between the copper and the aluminum.

These are 105 Ah cells and I'm considering a 2p16s pack for my golf cart. They suggest welding the tabs, but all I have is a mig welder and brazing torch, both of which would completely fry these things.

 

[rodrick]

Did they make those cells with a threaded hole like a 280n has if so find someone that has one and measure hole depth

 

[BroomJM]

Does anyone know how deep the material is between the aluminum tab and the top of the lithium phosphate cell inside?

Can these be drilled and tapped? I can't tell how thick that aluminum piece is or if there's anything under it that the drill could run into and damage. Obviously, practicing depth control will be important, but precision on a process like that can be difficult if the material is just too thin. Is there even enough material to tap a small machine screw thread? #8-32 or #10-32 ?

I'm thinking of bolting copper buss bars to these tabs using a set of stainless steel machine screws. Maybe 4x 10-32 screws going into each tab should provide adequate mating between the copper and the aluminum.

These are 105 Ah cells and I'm considering a 2p16s pack for my golf cart. They suggest welding the tabs, but all I have is a mig welder and brazing torch, both of which would completely fry these things.

I saw the same cells on BHU, I think. I'll be curious to see what folks say about how to make these usable.

 

[zcskywire2]

Does anyone know how deep the material is between the aluminum tab and the top of the lithium phosphate cell inside?

Can these be drilled and tapped? I can't tell how thick that aluminum piece is or if there's anything under it that the drill could run into and damage. Obviously, practicing depth control will be important, but precision on a process like that can be difficult if the material is just too thin. Is there even enough material to tap a small machine screw thread? #8-32 or #10-32 ?

I'm thinking of bolting copper buss bars to these tabs using a set of stainless steel machine screws. Maybe 4x 10-32 screws going into each tab should provide adequate mating between the copper and the aluminum.

These are 105 Ah cells and I'm considering a 2p16s pack for my golf cart. They suggest welding the tabs, but all I have is a mig welder and brazing torch, both of which would completely fry these things.

View attachment 147870

I wish I could express more on that cell (Gotion 105ah) but I have no manual, and many do not have the terminal thickness anyways.

What I can say is that I used to drill and tap m4 threads into EVE LF280s and LF280n cells. It is a very precise operation. There was a total of about 6mm of material we could drill and tap into. This required both the digital and physical stop on a drill press. The CALB datasheets show cells with 3mm or less of thickness. I wouldn't recommend doing drilling and tapping if you can avoid it. Especially without any info on the terminal thickness.

 

[MurphyGuy]

I wish I could express more on that cell (Gotion 105ah) but I have no manual, and many do not have the terminal thickness anyways.

What I can say is that I used to drill and tap m4 threads into EVE LF280s and LF280n cells. It is a very precise operation. There was a total of about 6mm of material we could drill and tap into. This required both the digital and physical stop on a drill press. The CALB datasheets show cells with 3mm or less of thickness. I wouldn't recommend doing drilling and tapping if you can avoid it. Especially without any info on the terminal thickness.

Considering purchasing a tig welder just for this.. Something really small in the micro-tig range.

 

[Crowz]

I watched a video of a guy building batteries from the cells (I can't remember where so sorry on that) and he was using a machine to weld the bars to the cells. Basically he applied the bar and then the thing just zapped it and went on. I have not clue what it was. I'll see if I can find it in my bookmarks. I suck soldering for the most part and figured if I ever built batteries I would need the thing since I didn't know there were bolt style ones to choose from back then.

 

[Crowz]

I'm guessing its a larger version of what this guy is doing that I watched.

Maybe a machine like this but larger?

https://www.amazon.com/Capacitor-Portable-Precision-Equipment-Building/dp/B09K3ZMBDL?th=1

 

[cs1234]

I'm not an expert on drilling, but since it's aluminum, it should be relatively soft. Can you use a hand powered drill of some sort to do it very slowly? Or maybe some small self tapping screws and then back em up and replace em with whatever machine screw you want?

 

[zcskywire2]

Please NEVER blindly drill a battery terminal. It is INCREDIBLY dangerous even with proper tooling and reference material. Threading a self tapper in is even worse as you have almost no reference to how deep you are. You can get extremely hurt and depending on the battery chemistry have a firey and not at all peaceful time. A electrical spot welder with nickel strips will be much safer though I cannot vouch for it's effectiveness on the large prisnatics.

 

[cs1234]

@zcskywire2
Thanks for heads up, I was just about to get started drilling some air holes into my batteries to cool them off faster. ?

 

[MurphyGuy]

@zcskywire2
Thanks for heads up, I was just about to get started drilling some air holes into my batteries to cool them off faster. ?

He has 50 posts and just joined.. Give him a break...

 

[SilverbackMP]

Watching this discussion on the welding aspect. I popped a terminal cap off of a Calb 230 AH cell on my second battery build on the final connection. They were attached with two thin impulse welds. Luckily had four extra (dropped and dented another one). Absolute pain to get this out of their boxes and out of their strapping tape to replace it.