I also did not want to do the modifications. The point of the modifications is two fold. Keep the inrush current when first hooking it to a battery, from stressing components on the PCB, and prevent the voltage falling so low during the weld, that the mosfet has issues holding the mosfet gates closed.
The inrush issue can be solved with using an XT90 Antispark connector between the battery and the welder.
The too low a voltage issue can be by using a dedicated 12v battery just to power the welder circuitry, but a separate 3S battery for the welding current. The battery powering the welder PCB does not need to be any high C rate battery, but the weld battery certainly does, but not too high.
There is a goldilocks zone, and any particular lead acid car battery might be within that zone, or it might not
I built 3 10s2P batteries with the Purple spot welder, 0.1mm copper and 0.1 nickel plated steel sandwich using a Zee 60C 5.2AH Lipo, but as that lipo aged I kept having to increase the gear/pulse mS, and consistency suffered and it got more and more difficult and stressful to use.
I used same exact Beefed up cabling/ Dual battery system for both the red and the purple welder and the Purple could weld the 0.1 copper under 0.1 NPS, but my red one could not
While I much preferred the interface of the Red, I almost never used it, in favor of the Purple. Using the very tedious infinite Slot method, I was able to get 0.15mm copper welded under 0.1mm NPS on a test cell, one sanded free of previous welds and the nickel plating, but these same settings on new cells proved too weak, all other factors being equal.
View attachment 380035
When my Zee Lipo failed, I was just reluctant to get another as I knew it was just going to work well for one battery and then degrade too fast, even when kept at proper storage voltage and temperature. I had a backup purple PCB ready to be swapped in if I smoked it mid battery build.
Zeus-FL then hooked me up with a AwithZ P20B, so these sit unused, and honestly, If I am in immediate need of 8AWG with an XT90, out come the wire cutters.
If I were to Use the Purple welder again, I'd likely get a high end 3S~ 5 Amp hour Lipo, and use 0.12mm copper, and 0.1mm stainless steel, and Flux. The Stainless and Flux decrease the welder power required enough I suspect this one would be capable of 0.15mm copper. I'd try it if I had a healthy 3S lipo on hand. I was unaware of the magic of Stainless steel, or the welding flux when I had only the purple and red welders.
This purple welder has a very loud annoying beep, which I neutered, but there is no easy way to hook up a pedal to it, it just fires a half second or so after both probes are placed on battery and this delay is not adjustable.
Getting them aligned right where desired, and the proper even pressure on the probes, before it fired, was kind of stressful, and I came close to ruining a few cells when the probe slipped off the strip and it fired automatically, and nearly blew a hole in the can.
On youtube, there are videos by Luca showing how to modify both the red and purple welders, and there are several different versions of the red, and even when modified, the purple outperformed the red, and he shows exactly how.
I did not perform the modifications, I just used the xt90 Antispark and 2 12v batteries, and the purple welder lives on, it is just not powerful enough for my desires, and the interface is too clunky, and consistency really suffers when the Lipo weld battery ages and the welder gets hot.
The AwithZ is luxurious to use in comparison. It is pricey, but Lipo's aint cheap either, and old ones limit the end result.
batteryhookup.com
