Battery Box

Nice job on the plywood box, spring loaded contacts on the positive side or do my eyes deceive me?

Thanks guys, Appreciated…. Yes sir Bob, one side of the contacts are spring loaded so each cell can push independently…. It’s on the negative side however…. The springs are soldered on to the tabs and other end is a friction fit into the holes bored part way into the box…The positive tabs on the cells contact the solid copper bar on the left in the photo …

I like it. Lot's of thought and effort went into it. Box nicely beveled and sanded, no sharp edges. A+++

Yes that is nice and the D size battiers do get a work out , but 4 is better that 2 LOL

Really nice work, Robert, 4 cells will definitely do a lot of good. I've used 2, but then ended up swapping them out mid season.

When I worked for the Bekesey Laboratory for the Geophysics Department at the University of Hawaii as a student (cheap labor), working on their ocean bottom seismometers, one of the tasks I did was unsoldering the Duracell D Battery pack (I think there were like 20 battery cells to make up say, a 30V battery pack. Provided the power for up to a month's down time in the ocean for the recording package.) Then solder in the new batteries.

With my supervisor's permission (they threw away the used ones), I took the used good ones (as close as 1.5V as possible, say at least 1.4V), made my own glow driver with 7 or 8 of these cells soldered together in series, good power for a whole season for free.
Worked like a charm, did this a couple times, and saved me the cost of batteries for a college student.