OK. I have been informed in badcaps.net forum that modern batteries BMS cannot be jumpstarted.
Once the controller locks the battery, the controller has passwords and also you need to reprogram the controller with special tools.

Hi. Trying to recover a battery for X380 Yoga. Nominal Voltage is 15V but it had only 7V and doesn't charge. My idea is that probably this battery was without use long time and it has auto discharged. So I disassembled it, it has 4 cells li-poly 3.82V. I charged them individually and now battery has...

Saucey wrote: ↑

Sat Jul 29, 2023 6:22 pm

Don't these machines "wake up" once receiving power when the CMOS battery and main battery are disconnected?

Correct. Disconnecting the CMOS battery the motherboard boots when connecting the power supply. Thank you.

OK, but I only have the motherboard. The power button is in this auxiliary board: https://i.ebayimg.com/images/g/32wAAOSw1wtfaGEJ/s-l1200.webp FORUM warning : picture(s) WAY too big, tags removed. Please read the Forum Rules , especially Section 5 : https://forum.thinkpads.com/viewtopic.php?f=16&t=1...

I have a X380 yoga motherboard, with fan and speakers i want to test.
There is no power button, it is a board apart connected to mainboard with a 8 pin connector.

I think you are right. I didn't see item's description: Type: DC Converter Plug, PD E-Mark Chip , https://ae01.alicdn.com/kf/S06cbaa59802d46fa8b902a440bed7010T.jpg E-Mark Chip: https://v4-upload.digoodcms.com/383/1574779175_E-mark%20chip%20(1).jpg So, I understand these adapters are safe, at least w...

I think they are passive adapters. Simple rewiring from old chargers to USB-C. So there are no comms. Always 20V.

My doubt is if a thinkpad x390 or x1 or x13 yoga can demand at some point while charging to lower the voltage, burning something.

Nobody knows? Is it perhaps a question for another subforum?

I have a new X390 Yoga with USB-C charger. I have old chargers from my other thinkpads. All 20V, with square connector and round connector (used for X230). And I have bought chinese adapters "square to USB-C" and "round to USB-C" in order to reuse my legacy chargers with the new laptop.I have tried ...