We see this a lot here at Pax Dealing with NMCI.... go figure.
The only fix is to get a new battery. Could be 3 problems
1. They are only designed for like 500 charges and Discharges. The problem you run into is if your Bat is in the laptop when you plug in AC power, its going to start charging. Even if its fully charged, the laptop will still try to charge it.
My advice is only keep the New battery in the laptop when your not on AC power. Let the battery fully discharge before your try to re-charge it. this will give you longer bat life.
2. It could be defective as well. Dell has had several battery recalls, but if the battery is a few years old they will make you buy a new one.
3. Motherboard is damaged and is shorting out the battery.