Lights4fun have an amazing customer service department which I have contacted a number of times now and they have been extremely pleasant and helpful. They have sent out a whole set of lights when the ones I received did not work at all and have since sent out new batteries to put in the other lights when they stopped working. However, the batteries are not the problem, I now have 4 sets , all the same, of lights for my garden and only one of them works. They worked for a short time after I bought them and then stopped when the winter came but have not started again! I am very disappointed as I love the small bursts of lights but one set working out of 4 is just not good enough, Sorry, Ellen Wilson