I take it you are not looking for batteries for you KM. As these button cells are relatively inexpensive.
Are you looking for AA equivalents. If so there are a number of options available. I've started using Uniross rechargables and they seem to last forever, maybe as they have a 2700mAH rating. You can get 4 batteries plus a charger ( from Amazon for £14.99. ) It's the charger I have and it comes with a car charging lead, very useful.
But shop around to see if you can get a better deal. I'd go for the highest rating you can get as that means they will last longer