Take a look at our
ThinkPads.com HOME PAGE
For those who might want to contribute to the blog, start here: Editors Alley Topic
Then contact Bill with a Private Message
ThinkPads.com HOME PAGE
For those who might want to contribute to the blog, start here: Editors Alley Topic
Then contact Bill with a Private Message
X1 Carbon Gen 4 battery charging issue
X1 Carbon Gen 4 battery charging issue
Rebuilding a parts-unit X1 Carbon Gen 4. So far replaced screen (known bad), coin cell battery (old) and main battery (reported by system as dead), New battery is off eBay. Installed the battery and the system booted right up, 84% charge, good battery health, and all looked fine. Ran it down in level a bit to work on other things, and then tried to charge.
When I insert the charger and the laptop is running, the power button starts flashing 2-blinks, pause, 2 blinks and the "plugged in" icon starts flashing screen. System does NOT start to charge. If the system is off, the orange charge light near the power port comes on solid, but system still does not charge.
I have done the searches and find nothing quite like this.
I have tried the power drain 20-45 secs, no joy. Held reset button for 10 secs, no joy. Disconnected coin cell battery for 10-secs, no joy. Disconnected and reconnected battery, no joy. Don't see anything in BIOS, or Lenovo Vantage (battery set to start charging at 75% but it doesn't). Tried two different Lenovo chargers, 65W and 90W no change.
Bad battery? New one on order, but ....
Any help or thoughts on this issue? The UG doesn't address the 2-flashes on the power button, just says a power issue is at fault.
When I insert the charger and the laptop is running, the power button starts flashing 2-blinks, pause, 2 blinks and the "plugged in" icon starts flashing screen. System does NOT start to charge. If the system is off, the orange charge light near the power port comes on solid, but system still does not charge.
I have done the searches and find nothing quite like this.
I have tried the power drain 20-45 secs, no joy. Held reset button for 10 secs, no joy. Disconnected coin cell battery for 10-secs, no joy. Disconnected and reconnected battery, no joy. Don't see anything in BIOS, or Lenovo Vantage (battery set to start charging at 75% but it doesn't). Tried two different Lenovo chargers, 65W and 90W no change.
Bad battery? New one on order, but ....
Any help or thoughts on this issue? The UG doesn't address the 2-flashes on the power button, just says a power issue is at fault.
Last edited by Scorpion8 on Mon Jul 14, 2025 6:45 pm, edited 1 time in total.
T490/495/E14 and X1 Carbon user.
Pain heals, chicks dig scars, glory .... lasts forever.
Pain heals, chicks dig scars, glory .... lasts forever.
Re: X1 Carbon Gen 4 battery charging issue
Updates
I cleaned all the battery connectors with DeOxit, ran all the updates, left it off but plugged in to charge for 8+ hours with no change. Charge is decreasing to the point of going on low power mode, but battery is not charging. And power button continues to flash 2x pause then 2x then pause....repeatedly when running and plugged in. Disconnect the battery and laptop powers on and runs fine (mostly, more on that later) but that's not a viable solution. New "genuine Lenovo" battery on order from eBay. We'll see.
The "runs fine" issue is also troubling. This laptop, i7-6600 8gb ram is a dog. Dunno why but it is incredibly slow. It will boot, give you the Windows tune, then the screen blanks for 10-15 seconds before you get the PIN prompt to start. Even once started, Windows is sloooooooooooow. Things like menus take often almost a minute to appear. Click on a taskbar program and it may or may not load, and if it does may take minutes to appear.
I need to get the new battery and charging issue fixed first. Also on order is a 500 GB M2 Sata drive to replace the OEM 128 GB drive, and then probably a full Windows reset.
Once it learns how to charge.
But regardless of the charging issue, this Gen 4 is a dog compared to my X1 Carbon Gen 3. Not sure why Lenovo considered this the next generation upgrade.
I cleaned all the battery connectors with DeOxit, ran all the updates, left it off but plugged in to charge for 8+ hours with no change. Charge is decreasing to the point of going on low power mode, but battery is not charging. And power button continues to flash 2x pause then 2x then pause....repeatedly when running and plugged in. Disconnect the battery and laptop powers on and runs fine (mostly, more on that later) but that's not a viable solution. New "genuine Lenovo" battery on order from eBay. We'll see.
The "runs fine" issue is also troubling. This laptop, i7-6600 8gb ram is a dog. Dunno why but it is incredibly slow. It will boot, give you the Windows tune, then the screen blanks for 10-15 seconds before you get the PIN prompt to start. Even once started, Windows is sloooooooooooow. Things like menus take often almost a minute to appear. Click on a taskbar program and it may or may not load, and if it does may take minutes to appear.
I need to get the new battery and charging issue fixed first. Also on order is a 500 GB M2 Sata drive to replace the OEM 128 GB drive, and then probably a full Windows reset.
Once it learns how to charge.
But regardless of the charging issue, this Gen 4 is a dog compared to my X1 Carbon Gen 3. Not sure why Lenovo considered this the next generation upgrade.
T490/495/E14 and X1 Carbon user.
Pain heals, chicks dig scars, glory .... lasts forever.
Pain heals, chicks dig scars, glory .... lasts forever.
-
axur-delmeria
- Senior ThinkPadder

- Posts: 4413
- Joined: Mon May 28, 2012 5:49 am
- Location: Metro Manila, Philippines
Re: X1 Carbon Gen 4 battery charging issue
Do you have the 45W charger, or the 65W one?
Many older Thinkpad BIOSes lock down the processor to a low clock speed when running without a battery and have a low-wattage charger connected. For the X seris from the X61 to X230, the low-wattage charger is the 65w, so it needed a 90w charger to run at full speed without batteries. I don't know if it's the same case for the X1 Carbon Gen 4.
Many older Thinkpad BIOSes lock down the processor to a low clock speed when running without a battery and have a low-wattage charger connected. For the X seris from the X61 to X230, the low-wattage charger is the 65w, so it needed a 90w charger to run at full speed without batteries. I don't know if it's the same case for the X1 Carbon Gen 4.
Planned Purchase: T480s i5-8350 FHD Touch
Impulse Buy: Thinkpad not named for safety reasons
RIP: X220 4291-C91 X61 7676-A24 760XD-U9E
Impulse Buy: Thinkpad not named for safety reasons
RIP: X220 4291-C91 X61 7676-A24 760XD-U9E
Re: X1 Carbon Gen 4 battery charging issue
I have used it with both during this rebuild and don't think there is any difference in performance. 90W right now. FYI, OEM was a 65W charger according to the PSREF, and it was slow as molasses then.
Last edited by Scorpion8 on Mon Jul 14, 2025 6:44 pm, edited 1 time in total.
T490/495/E14 and X1 Carbon user.
Pain heals, chicks dig scars, glory .... lasts forever.
Pain heals, chicks dig scars, glory .... lasts forever.
Re: X1 Carbon Gen 4 battery charging issue
Any help with the blink-blink-pause, blink-blink-pause sequence?
T490/495/E14 and X1 Carbon user.
Pain heals, chicks dig scars, glory .... lasts forever.
Pain heals, chicks dig scars, glory .... lasts forever.
-
axur-delmeria
- Senior ThinkPadder

- Posts: 4413
- Joined: Mon May 28, 2012 5:49 am
- Location: Metro Manila, Philippines
Re: X1 Carbon Gen 4 battery charging issue
Does that happen regardless of which charger you use?
Planned Purchase: T480s i5-8350 FHD Touch
Impulse Buy: Thinkpad not named for safety reasons
RIP: X220 4291-C91 X61 7676-A24 760XD-U9E
Impulse Buy: Thinkpad not named for safety reasons
RIP: X220 4291-C91 X61 7676-A24 760XD-U9E
Re: X1 Carbon Gen 4 battery charging issue
Yes. Only when powered on, the sequence starts. If the laptop is shutdown, I get the steady orange "changing" status light on the side. But it doesn't charge. As soon as I power it on, the blinking starts and does not matter which charger is in use.axur-delmeria wrote: ↑Mon Jul 14, 2025 8:13 pmDoes that happen regardless of which charger you use?
T490/495/E14 and X1 Carbon user.
Pain heals, chicks dig scars, glory .... lasts forever.
Pain heals, chicks dig scars, glory .... lasts forever.
Re: X1 Carbon Gen 4 battery charging issue
Still awaiting a new battery. No other updates.
T490/495/E14 and X1 Carbon user.
Pain heals, chicks dig scars, glory .... lasts forever.
Pain heals, chicks dig scars, glory .... lasts forever.
Re: X1 Carbon Gen 4 battery charging issue
So other issues noted while waiting for the new battery (which is going on a world tour, thanks USPS!):
Boot -- Laptop boots fine on wall-power, but after Windows music chime, the screen stays blank for an inordinate amount of time (say 10-15 seconds) between when the Lenovo logo disappears and the Windows lock screen pops up.
Boot -- Sometimes when the system boots and gets to the lock screen PIN, the keyboard does not respond to input to enter the PIN. A reboot usually cures this, but you never know when it will happen and when it will work fine.
Speed -- This thing is slow. Clicking on a program sometimes involves a wait of 20-seconds or more before any activity is seen. I have run the task manager processes and there doesn't seem to be anything unusual happening. Sometimes nothing happens and you have to re-double-click on a program to launch. It is only 8GB but even my Thinkpad Yoga 11E is faster than this on a Celeron N500.
Any experience with these issues before I try a complete Windows reset?
Boot -- Laptop boots fine on wall-power, but after Windows music chime, the screen stays blank for an inordinate amount of time (say 10-15 seconds) between when the Lenovo logo disappears and the Windows lock screen pops up.
Boot -- Sometimes when the system boots and gets to the lock screen PIN, the keyboard does not respond to input to enter the PIN. A reboot usually cures this, but you never know when it will happen and when it will work fine.
Speed -- This thing is slow. Clicking on a program sometimes involves a wait of 20-seconds or more before any activity is seen. I have run the task manager processes and there doesn't seem to be anything unusual happening. Sometimes nothing happens and you have to re-double-click on a program to launch. It is only 8GB but even my Thinkpad Yoga 11E is faster than this on a Celeron N500.
Any experience with these issues before I try a complete Windows reset?
T490/495/E14 and X1 Carbon user.
Pain heals, chicks dig scars, glory .... lasts forever.
Pain heals, chicks dig scars, glory .... lasts forever.
-
RealBlackStuff
- Admin Emeritus
- Posts: 24727
- Joined: Mon Sep 18, 2006 5:17 am
- Location: Loch Garman, Éire
Re: X1 Carbon Gen 4 battery charging issue
That laptop just has a lousy CPU, i7-6600U (only 2 cores, soldered) looks good on paper.
Does it have 4, 8 or 16GB RAM?
My oldie M900 (mini-desktop) has a 'measly' i5-6600T (4 cores, socketed) with 16GB RAM and literally FLIES through everything.
Compare those and weep!
You are probably also trying to run W11?
If so, use W10 Enterprice LTSC 2019 or 2021 instead.
Or be bold and go to Linux Mint.
Or be VERY bold and put MacOS on it!
I recently Hackintoshed my T480 (i5-8350U, iGPU, 32GB RAM) with MacOS Ventura.
Used an external SSD and it took me less than 2 hours to have it fully up and running.
Upgrade to MacOS Sequoia is next.
All that just for fun (I'm retired with plenty time on my hands).
Does it have 4, 8 or 16GB RAM?
My oldie M900 (mini-desktop) has a 'measly' i5-6600T (4 cores, socketed) with 16GB RAM and literally FLIES through everything.
Compare those and weep!
You are probably also trying to run W11?
If so, use W10 Enterprice LTSC 2019 or 2021 instead.
Or be bold and go to Linux Mint.
Or be VERY bold and put MacOS on it!
I recently Hackintoshed my T480 (i5-8350U, iGPU, 32GB RAM) with MacOS Ventura.
Used an external SSD and it took me less than 2 hours to have it fully up and running.
Upgrade to MacOS Sequoia is next.
All that just for fun (I'm retired with plenty time on my hands).
Lovely day for a Guinness! (The Real Black Stuff)
But I actually prefer Murphy's from Cork!
But I actually prefer Murphy's from Cork!
Re: X1 Carbon Gen 4 battery charging issue
This one runs Win11 and has just 8GB RAM, and yea that is a small amount today, but the performance is beyond miserable when compared to much lesser pieces of kit. Like I stated, a Celeron N500 in a Yoga 11e running Win11 outperforms this one. My T420 will scream past this machine, as will a similar configured X1 Carbon 3rd Gen. And some of the issues, like the long screen delay upon startup, and the glacial speed of responding to mouse clicks at times is a sure cause for Tourettes Syndrome. And no one has provided any info on the two power button flash sequence, so am wondering if there is an internal issue before I just throw in a new battery.
T490/495/E14 and X1 Carbon user.
Pain heals, chicks dig scars, glory .... lasts forever.
Pain heals, chicks dig scars, glory .... lasts forever.
-
RealBlackStuff
- Admin Emeritus
- Posts: 24727
- Joined: Mon Sep 18, 2006 5:17 am
- Location: Loch Garman, Éire
Re: X1 Carbon Gen 4 battery charging issue
You already provided the answer:
So we just wait until you have a new/better battery.Disconnect the battery and laptop powers on and runs fine...
Lovely day for a Guinness! (The Real Black Stuff)
But I actually prefer Murphy's from Cork!
But I actually prefer Murphy's from Cork!
Re: X1 Carbon Gen 4 battery charging issue
Well, by "runs fine" I mean it runs. Performance wasn't compared to on-battery versus no-battery-line-power.RealBlackStuff wrote: ↑Thu Jul 24, 2025 11:49 amYou already provided the answer:So we just wait until you have a new/better battery.Disconnect the battery and laptop powers on and runs fine...
T490/495/E14 and X1 Carbon user.
Pain heals, chicks dig scars, glory .... lasts forever.
Pain heals, chicks dig scars, glory .... lasts forever.
Re: X1 Carbon Gen 4 battery charging issue
Machine performance issue is 50-60% solved. This machine came from a business recycler, which got me thinking. Sure enough the drive encryption setting was ON, even after a Windows reset. This caused the lil' 2-core CPU to churn excessively. It is not a seamless background process, maybe on a late gen CPU but not on this i7-6500 2-core chip. Turning device encryption OFF resulted in a marked improvement. Oddly still not as fast as my Gen 3 X1 Carbon, which is odd, but there ya have it. Small improvements. This will never be my main device anyway.
T490/495/E14 and X1 Carbon user.
Pain heals, chicks dig scars, glory .... lasts forever.
Pain heals, chicks dig scars, glory .... lasts forever.
Re: X1 Carbon Gen 4 battery charging issue
An update. Compared my Gen3 X1 Carbon (8GB, i5-5600) to this Gen 4 X1 Carbon (8GB, i7-6500) and the Gen 3 blows this "newer, faster" machine away. Besides disk encryption, what could be throttling this machine so much? Is there a BIOS setting that I am missing?
BTW, "new" battery is here but not installed yet. Man, I wish I got those airline miles for my packages.....
BTW, "new" battery is here but not installed yet. Man, I wish I got those airline miles for my packages.....
T490/495/E14 and X1 Carbon user.
Pain heals, chicks dig scars, glory .... lasts forever.
Pain heals, chicks dig scars, glory .... lasts forever.
Re: X1 Carbon Gen 4 battery charging issue
New battery (Lenovo "branded") installed. Still shows two-flashes-and-pause, two-flashes-and-pause on power button. Charging icon appears intermittently but it is NOT charging, down from 74% upon install to 71% while idling doing nothing.RealBlackStuff wrote: ↑Thu Jul 24, 2025 11:49 amSo we just wait until you have a new/better battery.
T490/495/E14 and X1 Carbon user.
Pain heals, chicks dig scars, glory .... lasts forever.
Pain heals, chicks dig scars, glory .... lasts forever.
-
- Similar Topics
- Replies
- Views
- Last post
-
-
X1 Carbon 4th Gen -- Wonky Keyboard
by Scorpion8 » Thu Oct 23, 2025 9:40 pm » in ThinkPad X1 / X1-Carbon / X1-Extreme and later Series - 9 Replies
- 13252 Views
-
Last post by Scorpion8
Wed Nov 19, 2025 4:42 pm
-
-
-
X1 carbon gen 5 and 6 keyboard and power button assembly interchangeability
by dcfbf » Mon Dec 15, 2025 4:15 pm » in ThinkPad X1 / X1-Carbon / X1-Extreme and later Series - 3 Replies
- 8824 Views
-
Last post by dcfbf
Wed Jan 21, 2026 2:32 pm
-
-
-
Battery use and charging etiquette for Classic ThinkPads?
by johnny1093 » Wed Oct 29, 2025 1:50 pm » in Thinkpad - General HARDWARE/SOFTWARE questions - 2 Replies
- 12573 Views
-
Last post by johnny1093
Sat Nov 01, 2025 8:46 pm
-
-
-
Why is my P1 Gen 7 so much better on battery? Cool, quiet, fast — but not on AC.
by Frippe » Tue Nov 18, 2025 5:21 am » in ThinkPad P1/P14/P15/P16/P40/P50/P70 and later Series - 3 Replies
- 9337 Views
-
Last post by RealBlackStuff
Wed Nov 19, 2025 12:30 am
-
Who is online
Users browsing this forum: No registered users and 38 guests



