BIOS update of a Dell Linux laptop without a battery

27. november 2024

My previous laptop, a Dell XPS 15 9560, had a weird BIOS issue. When turning it on, it went into some sort of self diagnosis mode if I didn't intervene and explicitly told it to boot from the SSD.

I found a new use for the laptop, so I decided to try and flash a BIOS update onto it, hoping it would solve the issue. Which turned out to be harder than it should.

First of all, BIOS updates come as Windows .exe files. But I don't run Windows. Alright. When turning on the computer, you can press F12 to enter the Boot Options menu. From here, theres an item called BIOS Flash Update.

This starts a small utility that will do the BIOS update flashing if you plug in a USB stick with the .exe file on it. But this only only works if the laptop has a battery with a certain charge installed in it. And mine doesn't, as the battery stopped working a while ago, so I completely removed the battery. If no sufficiently charged battery is found, the BIOS udate is blocked by a message saying:

PowerStatus: Inadequate

Searching the interwebs led me to various "solutions" that all turned out to not work. One involved making a bootable FreeDOS USB stick with the .exe file on it, to execute it from there. Trying this gave me another error:

This program cannot be run in DOS mode

Another proposed solution was to hold down Esc and Ctrl keys while turning on the computer with a USB stick inserted with the .exe on it. This just brought me to the same self diagnostics thing that I was trying to avoid.

Some places said that adding a /forceit argument (and other similar arguments) when running the .exe in Windows would bypass the battery check. But I still wasn't running Windows.

I finally found out that these arguments can be entered in the Options textarea in the BIOS Flash Update utility.

So, the solution turned out to be:

Put the BIOS update .exe file on a FAT formatted USB stick and insert this into the laptop.
Press F12 when the computer is starting, in order to reach the Boot Options menu.
Select BIOS Flash Update.
Find and select the .exe file via the ... button.
Enter /forceit into the Options field.
The PowerStatus value should shortly after change from the red Inadequate to a green Forced.
Press the Begin Flash Update button to initiate the flashing.

This will probably also work on other Dell laptops with a similar BIOS setup. Make sure to keep the power supply plugged in during this, as there is no battery to help you i case the power plug is removed.