The "EXPENDABLES" movies are, objectively, awful - even by the incredibly low standards of the "Hey, remember when action movies sucked but sucked in a different way than they do now?" genre. The sole (and evidently sufficient) reason they have for existing are the handful of shots where a bunch of actors you remember from the 80s are standing together in the same shot and you can get 1/400th of the charge you might have gotten if someone had actually made "RAMBO VS. TERMINATOR" in the early-90s.
Outside of that, there's no reason to watch either of them. And now here's the trailer for Part The Third, which helpfully eliminates any further need to do so by simply having everybody stand a line and acknowledge that yes, they're in this. The "new" blood includes Antonio Banderas, Harrison Ford, Mel Gibson, Wesley Snipes and Ronda Rousey as We Couldn't Get Gina Carano: