I'm just wondering why you'd need to take books to a badminton training session. Anyway, Why not get the 7829? It's a nine racket bag so there should be plenty of space for all your stuff.
He might be taking his badminton rackets to the library. I have the 9820 and I find it to be magnificent - dedicated shoe compartment and room for all my kit/tools as well as rackets. Cheap, too.
yeh........ depends how many rackets you have and how books you plan on carrying. studying in between breaks at badminton sessions? lol...... like a lot of my friends. most of the newer model bags (any brands) usually have the 6 racket holder (2 compartments) and in the style of the backpack which is easy to wear 92 compartment, not costing as much as 9 compartment unless you have lots of rackets). If you have not many rackets, can use one compartment for rackets, and the other for your books. still has the shoe compartment and two other outer compartments for whatever you want
May be better to keep the rackets separate from your books then... I'll use a 6 racket bag for all the rackets + shoes + clothes and keep the textbook in the schoolbag. Most racket bags (except Wilson?) do not seem heavy duty enough to transport books.
personally i would try and keep my badminton stuff apart from my school stuff just cause not all badminton bags are designed to carry heavy loads espically lots of textbooks. personally i just use a small bag when i train in the mornings and carry my school bag as well. yes i know what your getting at that its more convient to carry just 1 than to have to take 2. but for me anyways its so much easier on the bags and on me too that i have 2 bags one badminton bag for equipment and my school bag. plus you dont need to bring much to training 2 racquets, a pair of shoes, and some clothing and accessories so not to much there. i do have a huge bag as well and i will occasionally (once a month maby) bring that to school only if i dont have any books/textbooks to bring and just 1 notebook or something to bring with me.