The negative end is sensitive to heat. I like the method of laying a copper ribbon on the negative end (*nickel-plated for corrosion resistance), and using a loosely constrained magnet to hold the ribbon onto the negative end.
The positive end has many options. If the heat of soldering or spot-welding concerns you, a connection can be made with a fuse-wire to the positive end.
The amount of heat from soldering or spot-welding a fuse-wire is much less than a full-sized bus strip.