This Dell Latitude E6540 laptop seems to be in good condition as expected, with virtually no evidence of wear or previous use.  No scratches or smudges.  The only problem is that the installed battery arrived DEAD and WILL NOT CHARGE!The first thing I did after opening the box was to plug in the computer to charge the battery.  After all night and part of the next day the battery showed 0% charge.  I wiggled the wires hoping that it had been a bad connection, but the little lightning bolt in the battery icon near the power button indicated that it had been "charging" all along.  To further check this, I went into the computer settings and confirmed that the battery was indeed "charging," but it also showed 0% charge after many more hours of being plugged in.Next, after first reading the instructions and cautions in the downloaded .pdf manual, I flipped the machine over, and pulled the battery out.  I checked to see if the contacts looked clean and in good condition.  Looked fine.  Gently blew on the contacts to remove any possible dust.  I put the battery back in, hoping it would work this time, but no luck.  Same thing -- 0% charged even though the indicators say it's "charging."  I think if the battery were not making good contact the system wouldn't sense that it was charging.  The computer works fine when it's plugged in, so it would seem that the battery itself is the problem, not the connection.Seeing as how a laptop is supposed to be portable, a working battery would seem to be rather fundamental.  This is obviously a pretty serious flaw, the cause of me rating the purchase at only 3 stars.  I realize that I bought a pretty powerful (refurbished) computer for less than $300, but I think it's a reasonable expectation that the battery will work.  I would have preferred a few scratches and smudges and a working battery!  A working battery would have garnered this purchase 4 stars.I have ordered another battery from Amazon for $69 (SUNNEAR 71R31 Battery 462-3678 9CELL 97WHR For DELL LATITUDE E6540/ E6440 ATG LAPTOP).  I'm assuming this will fix the problem, and even though I shouldn't have to buy a battery just to make this thing work outside the house, I will.  I don't want to go through the hassle of returning the whole unit just for the battery.  I will update this review when the new battery is installed and (hopefully) working.  We'll see.I can't give this purchase more than 3 stars even though the unit itself seems to be fine.UPDATE:  The new Sunnear battery charges just fine.  It's a $69 purchase (9 cell); I could have bought a 3-cell battery for about $39.  Anyway, the battery problem is solved by replacing the dead battery with a new one.  My review remains as 3 stars because it's clear that the computer was shipped with a non-functional battery.