So I was called back to do a preventive maintenance check on an instrumentation system that I had designed and set-to-work a previous year. The kit was a 19-inch rack of data logging systems to record sensor data from a marine test installation. It included a small uninterruptible power supply unit (PSU) with lead acid gel batteries as the short-term power backup. The environmental control was reasonable around the rack location, but as with all things waterside, there was warm, salty, moist air in the atmosphere.
I arrived on-site, got the briefing from the system users. The system had always worked well and had even kept going through several site power outages. Happy users. So I made my way down to the large, empty, dark warehouse where it was housed and opened the back door of the rack for inspection. This is what I saw around one of the back-up battery terminals (see the picture below). Close inspection with a magnifying glass (you have to zoom into the image to really appreciate the structures and colors) showed that it was not just simple crystal growth like I had played with as a kid. Now I'm no biologist, but whatever this gelatinous thing was, it looked to me as if had grown there, and it was organic. And why did it prefer the negative terminal?
Can anyone identify this peculiar growth?
What did I do? I didn't have the heart to kill it. So I carefully disconnected the cable to the cell at the inverter end, replaced with new throughout (checking I had properly tightened the connections up and smothering them with grease). I then made room in the rack to keep the old cell, complete with my monster, in situ. I even put a little 100K resistor in line so that the little beast would continue to be fed -- until the battery ran out. Adapt or die dude.
Our maintenance contract ran out the following month, so I never got back there, but I always wondered if the little guy survived. So if you ever hear of new life-form being discovered in the south of the UK, you now know its origin.
— Grover Mercer: "My background is 30 years of electronics and system engineering, including the manufacturing industry (wound component factory), physics research lab work and defense engineering in naval and land combat systems. Through industry trend, I have been sucked into software development, but I am at my happiest building little boxes crammed with electronic hardware that makes lights flash and things move."
Submit your product repair or redesign story as part of our Frankenstein's Fix competition on EE Life, and you could win a Tektronix MSO2024B digital oscilloscope. The deadline is October 26, 2013. Submission details and full contest rules here.
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