DJI RC remote batteries drain after 45 minutes

I have the DJI RC that I use with my drones. The battery life should be 2-4 hrs but I only get about 30-45 minutes of run time on mine.

In the past I’ve drained the batteries until the remote shuts down, then I’ve opened the remote and unplugged and replugged the batteries. After that the remote shows that it has about 65%-70% battery left, when I haven’t even recharged it from the first time. The remote then works great for a few more weeks, then it starts having issues again.

Any ideas to why this happens?

Is that because of bad batteries?

Bad software? (I’ve factory reset it 2 times)