This pretty much means a bad battery or charger. The early Dell 130W chargers seem to be affected by this problem far more then other Dell chargers. The easiest way to identify these troublesome chargers is to check if Dell is molded into the plastic enclosure on the blank side.
If you have determined you are dealing with one of these problematic chargers, it’s better to replace it with a newer unit. At this point in time, this is the charger you want: DP/N 0VJCH5 or newer. These don’t have any molding in them and the Dell logo is only found on the identifying label. If you're under warranty contact Dell and get it replaced. If you’re put of warranty, you’re probably going to be on your own.
If the BIOS complains, Dell usually tries the charger first. If it says "unidentified charger", then you’re not going to have a hard time getting it done; especially if it’s under warranty. If you need to use it and don't have a spare, it can be “fixed” temporarily but by NO MEANS is it permanent. It WILL permanently fail sooner or later.
That being said if you are out of warranty, it’s probably a good idea to do some additional troubleshooting. Check the indicator lights against this support document and you will know where the fault lies: E6540 diagnostic lights
If replacing the charger doesn't fix it, it's a battery problem. This is typically a undetected problem not flagged by the BMS where the battery wasn’t disabled. The BMS will always catch critical failures, but not all minor ones. These packs usually indicate this with a permanent battery failure POST warning. Replace the battery if you get this POST error or the issue persists.
If you replaced the charger and it's replacing one of the early units, keep it and stop using the early charger regularly - keep it as a working spare. Once it fails, scrap it. The early chargers are bad and should not be used in a mission critical environment.
What's wrong with these early chargers?
The early 130W units likely have problems with the 8 pin sense IC. This is bad since the BIOS reads it. If it can't make out what the charger *is*, it won't charge the laptop and may even throttle it. The only way for it to work correctly is for the charger to identify as Dell and register the wattage to the system.
Can I still use the charger?
Whether you can use the charger or not depends on the failure mode. If the sense IC is intermittent, you can often use the charger with the problematic sense IC, but it's just a temporary workaround. The charger needs to be replaced once this happens.
If the sense IC is so bad you can't get it to register at all (even with the workaround), you'll need to replace it to avoid throttling and be able to charge the battery. Order a new charger with expedited shipping to minimize (or prevent) battery damage.
If you need to use the old charger until your new one arrives, unplug the charger until the LED ring on the charger tip goes out. Once it goes out, try again. More often then not, this is sufficient to get the laptop to accept the charger again. Do this until your new charger arrives and ID the old one as bad so you don't mix the chargers up. Replace it ASAP once you identify the issue has happened to you. The sense IC may not last too long. It typically works for ~1-2 weeks, which gives you plenty of time to order it and receive your new charger. My experience is beyond 5 days, it becomes more difficult to get it to work. YMWV.