I just connect my charger to my car's battery. For most parkflyer batteries I can charge all day without concern.

That Harbor Freight generator will work but is noisy as can be.

I have also used car jumper packs. I have one hanging off the side of my workbench. Similar to this
http://www.amazon.com/Schumacher-IP-...=pd_sbs_auto_3

Unless you are flying REALLYbig planes with really big battery packs, use the car battery. Works fine.