Soldiers must use the bathroom during a tank battle.  Where is the
toilet located inside an armored tank?

Hi, 

No toilet is located inside the tank. As you can see with this cutaway
of the Tiger and Panzer tanks, there is very little room inside these
vehicles for anything except men and ammunition.
http://www.alanhamby.com/cutaway.html

Here is some information on the M1Abrams
http://en.wikipedia.org/wiki/M1_Abrams

Some good information and images are on this site as well. 
http://www.army-technology.com/projects/abrams/

Basically, like any other vehicle during war (such as helicopters and
jet fighters), you went as you could before and after fire fights,
or... well you just hoped that was your biggest problem.

thanks, 

webadept-ga

Good answer.  The links were very nice and interesting, especially the
cutaway view of a tank's interior.  One of the people that added a
comment said that an escape hatch in the floor of some tanks could be
used as a bathroom in an emergency.

I have to tell a funny story........
The OV-10 reconnaiscance jets have a relief tube for their male
pilots, which had a funnel shaped end so as not to miss.  The long
standing practical joke was to tell the new guy that it was a
communication device used to talk to the ground crew....go ahead and
try it.....as he put his lips to it and talked.....

Some tanks have an escape hatch in the floor which could be used in an emergency