got back from katawice a few weeks ago and had my electric chair with me.
1. find out if it is a gel battery or not - if not get the low down on what you need todo in order for it to get onto the airplane. the airline has the breakdown..
2. get there extra early, pray for a nice agent who will 'priority ship' the chair all the way to katowice, only if you are with air canada or luftansa can they do this.
3. while in the airlines hands do not move from the chair they give you as they are wonderful in Frankfurt and have a special room, and they always get you there and to the next airplane, again only air canada/luftansa and their reginal carrier.
its a great great experience and i wish you all the best.