Battery keeps getting discharged

I have a 99 Grand Jeep Cherokee Laredo 2WD 6 CYL. A couple of years back my battery went dead. At that time, the service shop, replaced spark plugs and also the battery. But since then, the battery has died multiple times,if I do not drive the Jeep for more than 7 days. The service shop replaced the battery couple of times since it was under warranty but the last time, he said it could be an electrical issue. What could be the issue? and how much $$ would it set me back? I do not want to sell the jeep at this point.

It sounds like there is a current drain problem alright. You should be able to park the car for at least a month and not have a problem. Normal current draw for most cars is around 25 milliamps or less. It sounds like you may have a draw that exceeds 100 milliamps. The shop should know how to check for this kind of trouble and I am surprised it didn’t do that already. Here is a helpful link that covers things about doing that.