After a couple of years with a Clipper Creek charger, I'm now a huge Clipper Creek charger fan. My Clipper Creek came with a long cord, it's quiet as a mouse, has worked perfectly, and they had a lot of plug and wattage options when I originally purchased (hopefully that is still true), so I was able to buy a unit that plugged into my existing 6-50 outlet, and I was able to get a 40 amp version to match the capability of my 6-50 outlet wiring. Awesome!
Really beats my prior unit, a GE Wattstation, that buzzed loudly while in operation, made an obnoxiously loud clanking sound from the contactor every time it turned on or off, had a shorter cord, was limited to 32 amps, and died after a couple of years.