I too just need a couple of more batts. To buy another charger just means I need to buy another converter to use it ......sigh.
Just a thought, instead of using another charger you could always put it away for when/if one of the ones you use regularly dies. I always keep a spare of everything (charger, adapter, PT, etc.) so when one dies I don't have to go without. Plus I get one when they are on a sale just in case when I NEED one there isn't a sale going on.