The datalogger doesn't do the same thing in other areas - so I think it is something to do with the compressor cycles of the fridge?
I'm not overly worried about it, just curious - I'll do it again soon and see.....
Had my Fondis C18 delivered yesterday anyway, to go in my as yet unbuilt cellar (construction to begin in ernest this weekend), so the cheap wine fridge will become inside pre-consumption storage only... Will post some construction pics if people are interested.
The Hisense fridge is advertised as 66 bottles, but must be for skinny Chinese bottles, as you can't get 6 across any shelf, of any 750mL bottle. Fits 5 shiraz type and a sticky OK though. Fatter pinot bottles are a VERY tight (label tearing) squeeze, and forget about champagne. Buyer beware 
 
Total storage would be about 55 skinny bottles, and 10 or so half bottles I'd say.