Maybe not the proudest, but here's a fun one for which my friend Nial Peters should get most of the credit. We were on Mt Erebus and I needed to power some 6V

Maybe not the proudest, but here's a fun one for which my friend Nial Peters should get most of the credit. We were on Mt Erebus and I needed to power some 6V carbon dioxide sensors for my work. We had lots of 12V lead-acid batteries, but we knew they were made up of 6 roughly 2V cells. We drilled a hole and put a screw in the middle. Now we had 6V batteries.