[Butz]

I don't know about too much power, because the spells would still have to hit (which if it's something like fireball or snowstorm, it seems to be a rarity), and it's not like they'd deal any extra damage.
Also, the fact that the player would be stuck there charging for so long to refill the wand kinda kills the idea of charging on the fly.
I mean, it probably shouldn't be a craftable item, because then people would have too many of them. It could either appear with the other wands in the shops once in a while, or be a reward for some quest (whenever we get a new one).
I don't know, I just get disgusted when as a sorcerer, I spend 20 minutes in the Tanarthia Haunted house trying to clear out the final room, and some warrior runs in with his super enchanted sword, kills everything in one hit, takes the treasure, and leaves me with a room full of monsters again. (And you're worried about the Magi having too much power?)
Anyway, just my ideas.
(Oh, and Kinatt, It's pronounced just the way you think it is. But it's because when I started playing Graal, I happened to have been on a "download translated Japanese Final Fantasies" kick. Final Fantasy V just happened to be the one I was playing at the time. ^.~ )