If it's not in the batch of batteries Dell would agree are defective, you can either live with it or buy a new battery.
Basically, your present battery is shot, but provided you have a power source nearby there's no harm in leaving it in place & just using the computer off the mains. Or it should work off the mains without the battery. If you choose to leave the old battery in, just check every few months that it doesn't leak. If it does, remove it & recycle it or the corrosion will destroy your computer.
If on occasions you need to leave the computer on without mains power, like transferring from one room to another, the battery will still probably have a few seconds life in it.
Some batteries can be encouraged to have a second life. When the computer is switched off, charge it fully. Then unplug & wait for any indicator light to go out. Then plug back into the mains & you should find it takes more charging & the battery may work as well as it used to, just that you have to charge it 2 or 3 times & switch off in between. One caution with this, the low battery warnings won't work so you could find the computer either hibernating or suddenly switching off & losing your work.
