Yes, it really depends on what charger you have, it should list "supported battery types" on the back, although if it's a household charger it may not be what you need. If it's not listed, then google it as Rainsong suggested. If it's not the correct type of charger, one can be obtained inexpensively online for a reasonable price. There are several trustworthy charger makers including Xtarr and Nitcore, to name a couple. I have a Nitecore Intellecharger two bay and it cost under $20 IIRC. The sleds were a bit rough to handle at first, but as I used it, they got a lot smoother, could also lubricate the sleds (I didn't know enough at the time to do it). Given my particular battery needs a two bay is really all that was required, but you may decide you want a larger charger.
Best of luck, and yes, external charging is very much the way to go. Mods designed for USB charging tend to use a safer chemistry for USB charge than internal battery mods, and the USB port is indeed useful for updates, but could wear out over time. I use a magnetic charger for all my (designed for USB charging) mods, because I find it to be much easier on the USB port, and if stepped on, knocked over etc., it will cause the magnetic cord to detach leading to much less USB strain on the port. Since I have a couple expensive devices that I HAVE to charge via USB (radiuses) I want to keep the USB port in good shape.... I got mine for about $3 from fasttech, but I really, really love it!
Best of luck and happy charging!
Anna