Has anybody extended the cord from the charge controller?

welcome! nope. get a good extension cord. determine how many feet you need, and buy the appropriate gauge. don't use romex tables, as stranded wire needs a heavier gauge. 25' of 12 gauge should be fine. get a good quality, or the connections might heat up.

there are plenty of threads here on extension cords. all the best!

 

I tried to remove that cord as well, needs a special tool nobody has. Just use an good quality extension cord, 14-ga if less than 20 feet, 12-ga if longer. I keep a couple 10-footers in my hatch storage bin.

 

I had to deliberately cut both my extension and my charge cord as they were wedged under the trunk edge. Have been operating for several months with both my sliced cords and have had no problems or hotspots. Should you venture to do this, get the proper size splice and heat shrink with a hot air gun for heat shrinking. And a good electricians tape wrap afterwards.

 

Probably the best solution.