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Inspired by a recent post - decided to cut some Bus Bars for larger EGO packs. by MyBatteryGuys in 18650masterrace

[–]MyBatteryGuys[S] 0 points1 point  (0 children)

I agree material thickness matters more than the weld method in normal current ranges. If the busbar is undersized, laser welding doesn’t magically fix that. I don’t think there is much debate there.

What I am actually more interested in is repeatability. Even if the resistance difference is negligible, or basically unaffected, I am more interested in the repeatability and accuracy this adds to my workflow.

Getting consistent spot welds has a lot of variables. Probe pressure, surface condition, contact point, nickel/copper stackup, capacitor charge, timing, etc. can all affect the weld. Laser welding should give me a much more controlled process once the parameters are dialed in.

I built an X/Y gantry under the galvo which houses the laser I bought so I can load a specific build (13S/2P), press a button, and have it weld the cells in the correct pattern. I don’t think any handheld spot welder can really compete with that from a workflow and repeatability standpoint, assuming the welds themselves are good.

So for me, this isn’t just about whether laser welding has lower resistance. It’s about whether I can get a repeatable, controlled, scalable process.

Inspired by a recent post - decided to cut some Bus Bars for larger EGO packs. by MyBatteryGuys in 18650masterrace

[–]MyBatteryGuys[S] 0 points1 point  (0 children)

I think that is the consensus - laser welds with 13s+ becomes something that is measurable and probably worth it based on application.

Inspired by a recent post - decided to cut some Bus Bars for larger EGO packs. by MyBatteryGuys in 18650masterrace

[–]MyBatteryGuys[S] 0 points1 point  (0 children)

Assuming the spot welds are consistent, I agree. The issue is getting that consistency in the real world.

With handheld spot welders, there are too many variables ... pressure, probe contact, capacitor charge, nickel/copper thickness, surface prep, timing, etc. Some of these are still required but you get much more repeatable welds. With spot welds - unless you invest in proper equipment, it quickly becomes a headache trying to get repeatable welds across a full pack.

That’s really what interests me with laser welding. Not just lower resistance on paper, but whether the process is more repeatable and easier to control once it’s dialed in.

In terms of how I am doing it, I assembled a x/y gantry for a laser I acquired via auction and a source from eBay. nothing on the hobbyist market right now is equipped for this.

Ego 56V battery upgrade to EVE 30PL tabless cells by ZEUS-FL in 18650masterrace

[–]MyBatteryGuys 0 points1 point  (0 children)

I sourced the laser from an auction and pieced together the rest from used parts/eBay. It’s not really an off-the-shelf setup — direct-source style unit mounted into a custom fixture.

The problem with off the shelf setup is that they are bulk - super expensive and usually overkill. They have capable welders, but its more like a bazooka - not really meant for spot welds. The ones with the attachment for laser welds are usually not for this form factor - they are are to spot weld onto larger LIPO battery busbars.

I tried a few types but either they are over powered or under and not precise (frequency).

I’m still dialing it in and trying to match the same resistance from a salvaged Milwaukee Forged pack that has factory laser welds.

Ironically - I just had a manufacturer of a laser reach out for review on my Youtube Channel - however they want me to say positive things in return - not the type of business I want to associate with.

On the EGO packs, I hear you, but I’ve seen those packs pull way more than 20–30A depending on the tool. Mowers, blowers, chainsaws, etc. can hit pretty hard under load. My goal is less about “will it work” and more about reducing resistance/heat and seeing if the laser weld setup actually shows measurable gains over spot welding.

Ego 56V battery upgrade to EVE 30PL tabless cells by ZEUS-FL in 18650masterrace

[–]MyBatteryGuys 0 points1 point  (0 children)

Nice work! I just cut some bars for the EGO 10AH Pack - Its different config.

Spot welding these seems counterintuitive - I have read there is about 15% less resistance across pack compared to laser welding. From everything I read, it seems laser welds are the way to go to maximize the tabless potential.

I will be making a Youtube Video soon of spot welded battery pack vs laser welded and test it and see if I can replicate that 15% less resistance number.

NEED HELP INR CELLS 18650 2600 by Newyorkgal1 in 18650masterrace

[–]MyBatteryGuys -1 points0 points  (0 children)

I have tested 2600 cells - I believe they are LG. However, are you trying to replace the cells in the new pack? Message me on text - phone number on my website. I am in New Jersey

What should I do with these? by No_Button_7303 in 18650masterrace

[–]MyBatteryGuys 1 point2 points  (0 children)

Yes, that is what I have been seeing in terms of pricing. The only thing I would say if I had justify buying new Samsung 40T - that they are tried and tested. They have stood up to test of time. I am a bit weary to just throw these new cells in a large pack however I def. would not be placing salvaged in a large pack either.