Batteries in my Rino 120 don't last very long

Check if the Ptt buton is not pressed by itself Check if all the features are running well because heat is not a good sing.

3 AAA batteries won't last long if your transmitting in higher powered GMRS. But if your not getting much time out of the batteries when just using gps, then it could be a few things. 1.. If your using rechargables you could have a bad cell thats no longer taking a full charge. 2.. if your using regular batteries use alkalines that are of good brand. 3.. The fact that the unit seems to be running hotter than usual could be another clue. A failed integrated circuit will usually draw alot more current. Usually what will happen in this situation if your hooked up to a power supply insted of batteries is the unit in question will get warm an draw more current slowly... the warmer it gets the more current draw... if you were using this on a power supply what would happen is it would eventually draw so much current that it will pop a fuse. In your situation your running on batteries.... the increase in current draw will just drain the batteries faster. Its a common problem with electronics... usually you can tell its a failed integrated circuit (IC) because the piece of electronics will blow fuses.... but not fast... sometimes it will take an hour for the IC to heat up enough and draw the appropriate amount of current to "pop" the fuse. At that point the IC is drawing alot of current. Thats a big clue.... a dead short pops fuses fast.... a bad IC will take a while to pop a fuse. Try checking the batteries as well as the advice in Solution#1 by sgregg. What could be happening is there is an IC that has gone bad inside the unit. The IC is running hotter and drawing more current as it heats up... causing the batteries to drain. Its just a guess.... its hard to speculate since I can't test the unit myself. Check the simple stuff first like batteries. Take care Bra

I believe its 3AA's and it SHOULD last 15 hrs of life. You should probably check the terminal heads and clean them real good you might be shorting somewhere in the connection.