spinningmagnets wrote:In order to keep the welder simple, the amps are adjusted by changing the amount of the battery amps.
So would the CCA of the battery be a better indicator of "weld power" than Ah? Most of the car batteries I have seen don't even have Ah ratings.
Car batteries provide more wallop for far less time, as SpinningMagnets said, they have more and thinner plates, designed to provide more wallop per turnover.
Leisure batteries have fewer but fatter plates, designed to provide less initial current but longer,deeper discharge cycles.
So a 100Ah 12v car battery would, all other things being equal, weld thicker strips than a 100Ah leisure battery...........but the leisure battery would weld more of thinner stuff.
It's all about getting a few batteries and testing.
With the old capacitance discharge welders, it was a question of getting good Caps and then adjusting the voltage for the material you were welding. 3 Farads at 12v did nothing. 3 Farads at 17v atomised the nickel.