What version of Windows are you running (Windows 10 or 11, Home or Pro)?

If you are running Pro, do you have BitLocker enabled?

If BitLocker is enabled, you may need to disable it in order to upgrade the BIOS.
Refer to the "Installation Instructions" on the driver page. "Before updating the BIOS, ensure that you suspend BitLocker encryption on a BitLocker-enabled system."

Dell G15 5515 System BIOS | Driver Details | Dell US

Hello,

Mine is windows 11 pro. while updating from BIOS 1.6 to 1.7 ESP disk error appears.

inspiron 5515 amd processor.  no bitlocker.  

error while bios update from 1.8 to any later = ESP disk space not enough!

Try the following: open the Command Prompt as administrator. Run "mountvol y: /s" to mount the EFI partition. Navigate to /efi/microsoft/boot/fonts and delete all the fonts (*.ttf). Reboot and run the BIOS update.

Same problem here with my G15 5515, when trying to update the BIOS from 1.6.0 to 1.7.1, I'm getting "ESP disk space not enough" even though the installation program disables BitLocker at the beginning.

I have the same problem!
Do you have the original ssd?

I don't know why you folks are getting the error but it should not be happening.  The suggestion regarding removing the fonts may help, if not look at the link.

Solved: Re: BIOS upgrade fails as not enough memory - Dell Community

I removed the fonts from the EFI partition, but the problem is still there. Unfortunately my pc is a work laptop, thus I can't freely format and play around with partitions. Is there any other unnecessary thing in the EFI partition that can be removed to make space?