This is very frustrating! I just got a new battery and this morning my Pathfinder won't start - nothing - zip! Before it wouldn't start this morning I did have a warning alarm to come on and I pushed the button. My neighbor helped with jumper cables. Naturally being an older car, it's not under warranty. Do you think they gave me a bad battery or is it something else?
You may have gotten a bad battery but I think the system in your vehicle is draining the battery and not recharging it. The alternator is the most common cause of this, or you have something staying on after you shut the vehicle off. Check if the interior lights, hood light, and brake lights go off. If any of these stay on, it will kill the battery overnight. If you cannot find the problem then leave the battery disconnected overnight after it is charged up and connect it in the morning to see if it starts okay. This tells you the battery is okay. If you need help, have a certified mechanic come and check the system for you, they will be able to properly diagnose your starting problem.