I got one to charge a 10 cell pack I have for another use.. bicycle lighting. Most cycle light chargers take 3 hours minimum but on 24 hour mountain bike races, I sometimes only have an hour between my heats. A second pack would be cheaper but a second charger is better as it can be used for RC
I also needed a second charger now that I have enough packs for all day flying and I don't like to push NiMH past 1C. It works great, especially on the automatic cycle/charge function for my NiCd packs.