Panic alarm goes off when I try to replace the battery. no after alarm system installed

possible -but all these fancy electronics are beyond the realms of most people and you need the factory to reset and diagnose the fault .even us mechanics have to admit defeat with faults like this and return vehicle to the dealer then charge for the time involved in taking and collecting the car ,take it straight to the dealer yourself

Aftermarket alarm system?? If so it could be anything with that alarm. If it's the factory security system, this is totally normal. When you disconnect the battery and reconnect it, the system resets and automatically "panics" because it saw the power failure. If it's the factory system, simply have the key fob handy to turn it off after you connect the battery. If you don't have a remote fob, just put the key in the driver's door and unlock it. This will override and shut off the system.

On some models you can disable the alarm after you connect the battery by locking and unlocking the driver door with the key.
I would disconnect the horn or pull the relay until you can get the alarm turned off.

Here's some info as it sound like the theft deterrent is armed.

---
Reset Procedure

NOTE: This information applies to a Vehicle Theft Security System (VTSS) that was armed when the battery was disconnected and reconnected.

When the armed VTSS senses that the battery has been disconnected and reconnected, it enters its power-up mode. In the power-up mode the alarm system remains armed following a battery failure or disconnect. If the VTSS was armed prior to a battery disconnect or failure, the system will have to be actively or passively disarmed following a battery reconnection.

The power-up mode will also apply if the battery goes dead while the system is armed and battery jump-starting is attempted. The engine no-run feature will prevent the engine from starting until the alarm system has been actively or passively disarmed.

Passive disarming of the Vehicle Theft Security System (VTSS) occurs when the vehicle is unlocked using the key to unlock either front door or the liftgate. Active disarming of the VTSS occurs when the vehicle is unlocked by depressing the Unlock button of the Remote Keyless Entry (RKE) transmitter.

Once the alarm has been activated (horn sounding, lights flashing, and the engine no-run feature), either disarming method will deactivate the alarm.

Depressing the Panic button (if equipped) on the RKE transmitter will also disarm the VTSS, but the horn will sound and the lights will flash for about three minutes as part of the Panic feature. The horn and lights can be stopped by pressing any of the RKE transmitter's buttons or driving the vehicle above 15 mph.

this is a test, please ignore

sound like an arm/disarm switch is going bad inside one of the doors causing the security system to activate.

try replacing remote batteries, but must have a second programmed key to reset first one in case its gets uncoded, best advise do not take long time to replace battery, if problem persist have a good honest mechanic inspect door key cylinder security switch if it is not disconnected, but before you do this, if right side front door or rear door has cylinder try opening vehicle from this doors, if they unlock vehicle and alarm doesn't go off you might have problems inside driver's door cylinder switch, on this year vehicle must use STAR SCANNER from chrysler jeep dodge to solve problems

If you are close to the truck when it happens, try removing the battery from the remote. Some times when remotes are worn, they can send out a constant signal setting off the alarm, unlocking the doors and so on. I would try that first. If it stops, then you verified the remote is the problem

Thanks Jay!

Replace the baterry to deactivate it.Thats the only way your going to do it.

Get a new battery. If it even starts to get weak, it turns the alarm system into a nightmare. I've had 2 Gr. Cherokees, had the same issue with both, as did a friend.