Check refurbished items, especially electrical, thoroughly!
I bought two of these, they are very good UPS battery backup devices. It states that the battery has been replaced as part of the refurbishment. No problem with the first one, but I just went to install the second one and I knew there was something wrong as soon as I got it out of the box.
Fortunately, it was just the battery cover not installed correctly when the replacement battery was put in, and I have rectified it. It has powered on okay so going to charge it up and see what happens. The APC one that it is replacing, the battery was dead, but it’s been in there several years. TV equipment in the living room. I have found that replacing the batteries in the APC ones doesn’t give good results because you can’t recalibrate them. Hoping for better luck when the battery in this one ceases to function.