Without getting into the boring engineering details of it all, lightning protection is a good idea for the chargers. I would definitely encourage you to purchase it, especially if it's inexpensive. The only thing to remember is to maintain it according to any guidelines provided with it. Not maintaining it according to their documentation will render it useless after a period of time. While you may never have need for it, if you ever see lightning in your area, then it's worth buying.
Didn't mean to semi-"nerd out" on you. Lightning protection is a part of what I do for a living, so I'm a little familiar with it. :)
The wind of heaven is that which blows between a horse's ears. ~Arabian Proverb