How to update Lenovo BIOS on a T460 without battery?

After a month searching the internet, I finally got my Yoga X1 Gen2 bios updated without battery. It was much more simple than I thought.

• download the official bios on lenovo support page and extract it.
• Run WINUPTP64.EXE or WINUPTP.EXE using command line with "-sp" option.

In my case, in CMD, I typed: C:DRIVERSFLASHn1nuj30w20210302.08305818/WINUPTP64.EXE -sp

Command line options:

   "  -s        ... Silent moden"
   "  -r        ... Reboot after program completedn"
   "  -sp       ... Skip power status checkn"
   "  -chk      ... Check current TPM firmwaren"
   "  -suc password ... Skip user confirmation at startupnn"
   " Note: -suc option requires supervisor password.n"

source: https://thinkdeploy.blogspot.com/2017/11/tpm-firmware-update-utility.html

Following info and steps worked in my old lenovo

The bios zip file includes:

• 2 files .FL1(BIOS) and .FL2 (ECP: Embedded Controller Program / platform)
• executables with a name similar to winphlash (can be DOS or windows)

winphlash can backup current BIOS and apply a BIOS with extension .ROM and will not check for battery.

The .FL files have the format required by winphlash, so you can rename the extension FL1 to ROM or just force the filter to pick the FL file

I managed to Flash the FL1(BIOS) and it is recognized and works.

However I didn't know what to do with FL2 file, I tried to flash as i did with BIOS but I received a warning message saying that version and code is not the expected.

(update: ECP should always be flashed before than BIOS)

Anyway, despite the message I flashed the ECP/platform ROM and everything worked well.

BTW I don't consider buying a new battery the best solution. Because in the practise not all people need a battery and for old laptops the cost can be similar to the laptop price.

Lenovo requires a working battery, decent charge (at least half) and plugged into AC. This is to prevent possibly bricking the BIOS chip. There is not a facility within the Lenovo BIOS update application (and looking through the documentation) to update with no battery.

I have done lots of Lenovo (and IBM) BIOS updates for myself and for clients.

I have ordered parts during COVID. Try Lenovo Sales Support and also 3rd party suppliers with warranty approved parts.