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BCDrums, I've been impressed with Cygolite for years. I had a couple of Hotspots, the kind that charged with a USB mini connector. One of them went bad, and I wrote to the company. They said they could replace the battery for about half the cost, so I agreed. They sent me a brand new unit. It's bright and sturdy, and it's great to have a responsive company. They make their products in USA.
I suggest you try getting a refund or replacement if you still have yours.
Now they have the Hotrod which I think charges with a USB micro connector.
I think I like USB C type connectors for durability and reliability, so I'm interested in knowing which taillights have this. I think I want a versatile mount since I move my lights from bike to bike.