I forgot and left the AA cell in this circuit and I paid the price heavily. The AA cell leaked and corroded the battery holder so bad it’s going to the trash can. And by capillary action, the battery juice wicked up the black wire, around the switch and came out the end where the solder joint connected it to the other wire, right below the switch – you can see the blue-green corrosion in the photo. Fortunately it didn’t get to the switch, which is an expensive and uncommon push on, push off type. But the black wire is also ruined and I wouldn’t trust the red wire.
The AA cell says “may explode or leak and cause injury” It should say “will leak and ruin equipment”.
This is another reason why I like using the small neodymium magnets for holding the wires to the AA cell. If the battery electrolyte gets on them, it usually scrapes off easily and nothing is harmed. Every plastic battery holder that gets corroded ends up with poor connections – the cheap rivets they used don’t make good contact, and the spring is usually so rusted that it can’t make good contact. I tried repairing them way back when, but now I just dispose of them and get another one from Radio Shaft for a dollar or else buy a handful online when I’m ordering other parts. I’ve been pretty lucky the last few years, because I’ve been diligent about removing the cells from the holders when they aren’t used, and getting rid of the old cells – they end up lighting several Joule Thiefs on a shelf.
