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Problem with one of the batteries of the T450s

Posted: Wed Sep 11, 2019 11:07 pm
by LawStudentWithThinkpad
Hello, new member here. Been lurking but I decided to join after watching some youtubers mention this site.

So I have a T450s, nice machine running Windows 10 on a SSD. However, since switching workplaces and then entering law school I had to put it on the shelf for a year or so after having its PLEX/FLEX? cable repaired. Yesterday morning, when I booted it just to check some old files from my first workplace, there was a message that one/both of my batteries were not genuine Lenovo ones and it warned that it would not charge. When I got into the desktop, Battery 1 (is this the internal one?) was at 0% and not charging, and Battery 2 (I guess this is the external one?) was charging just fine. What could have caused this problem? It has never done this before. Do I have missing drivers, firmware, or did someone swap one of my batteries at the repair center without me knowing it? What are my options? Thanks for the helpful replies in advance.

P.S. Going to post images of said error on the screen later for reference.

Re: Problem with one of the batteries of the T450s

Posted: Wed Sep 11, 2019 11:18 pm
by axur-delmeria
One of the things you shouldn't do is keep a laptop on a shelf for months as a time.

The lithium-ion batteries inside self-discharge, and when the voltage gets too low, the BMS (battery management system) red-flags the entire battery pack as a safety precaution .

Re: Problem with one of the batteries of the T450s

Posted: Wed Sep 11, 2019 11:26 pm
by LawStudentWithThinkpad
axur-delmeria wrote:
Wed Sep 11, 2019 11:18 pm
One of the things you shouldn't do is keep a laptop on a shelf for months as a time.

The lithium-ion batteries inside self-discharge, and when the voltage gets too low, the BMS (battery management system) red-flags the entire battery pack as a safety precaution .
I see, how do I un-red-flag it? What are my options now? Get a new internal (or is it external, how do I figure out which one was labeled non-OEM/non genuine?) battery? Switch to a Linux distro?

Re: Problem with one of the batteries of the T450s

Posted: Thu Sep 12, 2019 12:35 am
by axur-delmeria
No practical way to un-redflag it; IIRC a safety fuse inside the battery pack gets tripped when the voltage drops to 0v, which means you have to crack open the plastic shell, then have enough electronics skills to find said fuse and remove it. Oh, and there's also the matter of finding and purchasing said component in the first place. :x

In other words: it's much easier to just replace the battery pack.

Re: Problem with one of the batteries of the T450s

Posted: Thu Sep 12, 2019 12:39 am
by LawStudentWithThinkpad
axur-delmeria wrote:
Thu Sep 12, 2019 12:35 am
No practical way to un-redflag it; IIRC a safety fuse inside the battery pack gets tripped when the voltage drops to 0v, which means you have to crack open the plastic shell, then have enough electronics skills to find said fuse and remove it. Oh, and there's also the matter of finding and purchasing said component in the first place. :x

In other words: it's much easier to just replace the battery pack.
I see. What's the FRU for the internal battery? I was planning on getting a 72whr external battery, so might as well replace both. Is replacing the internal battery an easy thing? Just remove defective battery, then pop in the new one?

Re: Problem with one of the batteries of the T450s

Posted: Thu Sep 12, 2019 12:59 am
by axur-delmeria
For disassembly instructions, it's best to grab a copy of the T450s Hardware Maintenance Manual (HMM): https://download.lenovo.com/pccbbs/mobi ... g54937.pdf

You can also look for disassembly videos to supplement the instructions found in the HMM.

There's also an FRU listing available online: https://download.lenovo.com/parts/Think ... 160115.pdf