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Yes, I tested two of them but I didn't try moving them around after plugging them in. They fit into the jacks snugly and hold at 13.3V if I leave them alone. I just went and tried wiggling them around a little and they still held at 13.3V. However, I noticed that if move it forcefully enough to back them out of the port a hair it disconnects. So I think maybe the center pin is a little short rather than narrow.I ordered some of these, and just soldered them up. They seem to only *almost* fit. They slide in perfectly, but I think the inner pin is just barely to narrow. If I prod the outside of the connector I lose voltage. Did you test actually connecting it up?
I'll see if I can find one with a longer barrel and pin.