Walking In Guernsey | Tips To See The Sights

I recently broke my digital camera charger and I have had a bit of a search on the old internet and come up with a site that has a fair few Battery Chargers at quite a cheap price. I was wondering what the risks of buying a charger that is not the correct the brand for your camera? Does it have any effect at all on the life expectancy on your battery like the shop folk will have you believe?
I have long been under the assumption that it would, but I can’t decide whether or not I am just falling for the hype, which I invariably could be. The truth is, after recently splashing out £70 quid on a new battery charger for my laptop, I could really do with paying a lot less if it is possible and not really that important? Who knows best?
Talk to me people.