I noticed a strange and annoying behaviour of my battery.
If I shut down the computer when it still has about 40-50% battery charge and boot up again the next day, the battery has only about 5-6% battery charge left. This is really annoying, it jumps from 40-50% to 5-6% within a few seconds.
Today's batteries do not last as long as older models since the design has been changed. Be careful about replacing batteries. Lots of scams online with batteries. You need a genuine Dell battery from Dell or Dell Parts which might not be available. If you can't find a replacement from Dell, remove the battery when it dies and use the adapter alone. You should check the battery for any signs of trouble.