Recently bought a 2000 montero limited replased battery but next morning the battery was dead after driving it about 100 miles. I jumped it to get it started let it run and then checked the battery and charging systemand everything checked good but the battery was dead again the next morning. I have made sure all accessories were turned off but have the same issue the next morning. Any suggestions?

For a battery to go dead on you like that there must be something draining the battery while the vehicle is switched off. It could be something like a trunk light which is not switching off or a short across some circuit that does not show up on any light. The first and easiest test is to disconnect the battery negative cable whenever you park the vehicle overnight etc. and see if the battery still runs down.
As a more positive step and if this does not affect the alarm, disconnect the positive lead from the battery and wire a bulb like a tail light bulb, between the terminal and the removed lead. The bulb should light up. Make sure that everything on the vehicle is switched off, the bulb should still be lit. Remove and replace the fuses one by one until the bulb goes out. That is the circuit that is running your battery flat. Check all the components on that circuit until you get the light to stay out and your problem should be found.