Today my wife gave me a little box of solar-powered Christmas tree lights. She bought them last year 2019 but had forgotten she had them so it was only today (a year later) that I took them out of the box. These lights consist of a small solar panel wired to a rechargeable solar battery and an alkaline battery plus wiring which connects the circuitry to a string of 100 little LED lights. There are no moving parts that I can see.
I took everything out of the cardboard box and placed the components onto a white melamine table in our living room and screwed the connector for the wire from the LED lights string into the back of the solar panel box. Then I turned the solar panel itself up to the light within the room - which wasn't particularly bright as I was indoors. None of the LEDs glowed at all, so I assumed that I would need to place the solar panel outside in bright sunlight for some time to gain enough 'light energy' to power the LEDs. But then .. I accidentally knocked the solar panel box face down onto the white melamine table and the LEDs lit up. Every time I picked the box off the table and turned it to face the room, the LEDs went off, and every time I turned the solar panel to be back face down on the melamine table - the LEDs lit up again. I have left the solar panel box lying face down and the LEDs have now been lit for 3 hours and are fairly bright.
So my question is this: the solar panel is face down on the table so no room light or natural light or solar light can strike its face, and I think that even if I was to black tape around the box (i.e. stick it to the table) that wouldn't make any difference ... so from where is the solar panel deriving the energy it needs to light the LEDs?
I have removed the alkaline battery and the LEDs still light; if I remove the solar battery then they go off because that surely breaks the circuit between the solar panel and the LEDs. If the solar battery had had charge after 1 year in the box, then surely the LEDs would light up when I turn the solar panel away from the table wouldn't they? What am I missing here, please?