I'm VERY dissapointed (borderline angry to be honest) AT THE SELLER for wasting so much of my time!I'm a computer tech who buys computers for others (clients) and I know what refurbished means but it's the last time I buy refurbished units online (without seeing the unit first).FIRST UNIT I RECEIVED:1. There was a pretty big (roughly 1 inch) piece coming out of the back. It's the battery (I removed it to be sure) which does not show on any of the pictures (product description).  (see first 3 pictures on my review). It is a genuine DELL battery and that is what you want otherwise you'll have sudden shutdown problems.2. A plastic piece just above the cd/dvd drive was missing (as seen on the picture 1 & 2) so it left a pretty big open gap on the side. Gap where all the dust can sip inside the laptop over time and possibly ''block'' or dirty the drive's laser lens or worse.3. THE HARD DRIVE DESCRIPTION WAS WRONG! IT was NOT A SSD (Solid State) BUT A REGULAR 5400 rpm 500 GB HDD DRIVE!!!I contacted the seller via Amazon's feedback. The next day I got an answer back offering to replace the unit (return UPS Express pre-paid shipping label included). I waited 2 weeks to get the replacement (mostly UPS's fault as they are super slow these days)----------------------------------------------------------2ND UNIT (REPLACEMENT):Same model number Latitude E6540 but slightly different. No more gap on the side (plastic door was there. This one had a fingerprint reader and a 480 GB SSD but the battery was different (did not protrude in the back of the laptop).This one would suddenly and RANDOMLY SHUTDOWN for no apparent reason when plugged-in AC (happened 10 times within the first 24 hours). I did all the troubleshooting I could (ran Dell ePSA diagnostics=all hardware tests passed, updated BIOS and all drivers via Dell Assist Support, updated to latest Windows 10 bld 2004, etc) but issue remained. While running the tests I saw a claim in the BIOS (see picture #4) saying that ALL DELL laptops MUST use a GENUINE DELL BATTERY/AC ADAPTER to work properly. This battery was third party in poor health condition. Did some internet searches and found out that many others had the same shutdown issues on refurbished units using non-Dell batteries (one guy purchased 7 units and they all had the issue. A DELL tech confirmed to him that he MUST use GENUINE DELL BATTERIES ONLY).I removed the battery and booted in BIOS. Left it on for hours and NO SHUTDOWNS! Checked on DELL.com and a genuine battery is CDN$230.00 = not worth it.I will return this unit and ask for a FULL REFUND.***This unit was built in 2014 so it's now 6 years old. I PAID CDN$549.00 2 WEEKS AGO FOR IT BUT THE PRICE WAS NOW BUMPED UP TO CDN$699.00.  It was an ok deal at $549 but $700 is quite overpriced in my opinion since you can easily find new unit in that price range.My review of the laptop itself at $549 (with 500 GB SSD + new genuine Dell battery) would have been 5 stars ...