Battery/Charger recognition problems, cannot update BIOS on XPS 15z

Hi there.
I started having problems three days ago, where the power light began blinking orange and white, and the computer did not recognize the battery (there was also no "plugged in" icon). It was plugged in to the AC power cord, but if unplugged it would crash and shut down. Since then, I have checked the battery (no battery issue) and after removing and putting it back in, the computer now registers that the battery is in, and pulls power from it normally. However, the battery will not recharge, and no icon is displayed when the computer is plugged in to the AC power cord. When plugged in, the battery does not drain, but stays constant.

I am (less than a month!) out of warranty, so have limited options.

I am trying to update the BIOS, but without my computer registering the AC charger, it won't let me. Instead, a window pops up saying I must have but the AC adapter and the battery in to flash the BIOS.  Both things are in.

Some people have reported that updating the BIOS resolves his problem. How can I do this without the computer registering the AC cord, even when it's plugged in?

(Command prompt "forceit" overrides I've tried don't seem to do it)

Any help or suggestions appreciated.

Thanks