"Ivan Vegvary" wrote: (clip) Can present day batteries be tapped somehow?
Any ideas?
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Those bus bars must still be there, only covered with tar, or other black
insulating material. I suggest you figure out where the correct bus bar
ought to be, and try digging down to see whether you can make contact. You
might just try probing with a meter lead. If you find the spot, run a
self-tapping screw in and connect to it.