@g.jacobse @thecreativeone91 18650's are Lithium ion, which are plenty freaking dangerous! Batteries and caps are the only things that really scare the poop outta me in electronics.
For the charging/discharging/maintenance/safety stuff you can get cheap LI pack minders on ebay with a full LCD screen and all the goodies. Then you roll your own enclosure (mine will be sheet steel, a project box or wood). I will also integrate a speaker and amp in mine so when I go camping I've got tunes + battery charger for phone.