Hi all, I am currently using a MacBook Pro 15" mid-2014 with the following specs:

• RAM 16 GB 1600 MHz DDR3.
• Processor 2.5 GHz Quad-Core Intel Core i7.
• Graphic cards Intel Iris Pro 1536 MB/NVIDIA GeForce GT 750M 2 GB.

It is running with Big Sur 11.7.9. Recently, I had its battery replaced because my old one was in bad shape, and it had even swollen a bit. The new battery is from the manufacturer Simplo, according to coconutBattery app.

I've been experiencing some issues, particularly when using macOS on battery power only, something I hadn't done in a long time due to the poor state of my previous battery. The problems I'm encountering are as follows:

1. Overall slowdowns, laggy cursor, and beachball, especially when the battery percentage drops below 80%, most noticeable when it goes from 60% to lower.
2. Freezing my Mac, causing macOS to crash and returning to the login page.
3. In the worst-case scenario, a kernel panic, followed by a reboot.

Through my investigation, I have identified two processes, configd, and powerd, as the main culprits. Configd always uses 100% of the processor when the battery is the power source and I'm engaging in moderate to heavy usage with my Mac.

By this, I mean using applications like Spark mail, Safari, Activity Monitor (to track down issues), Telegram, Evernote, Todoist, Discord, and occasionally Notion and Element app without any image or video processing apps (which I would refer as heavier usage).

Reproducing these issues is quite simple – just let the battery drop below 80% and start using the aforementioned apps while unplugged. If issues arise, quickly plug it in, and you might regain control (though sometimes this approach doesn't work, depending on how long it remains stuck).

While I've found some information about configd and its behavior, the available advice mainly consists of workarounds, like manually killing the process (which doesn't work in my case because it auto restarts quickly). The closest source I've found addressing this is a macrumors forum, which also happens to be from this year. I also found a comment that describes my experience accurately.

I'm wondering if this might be a hardware failure or perhaps some kind of battery-related issue (battery gate, maybe???).

I also use BootCamp with Windows 10, and I haven't noticed any slowdowns or crashes when running on low battery. It seems to be isolated to macOS albeit my usage on Win10 is minimal compared with macOS.

Here is a list of workarounds and fixes I've attempted so far, without success (in what I believe is chronological order):

1. SMC and PRAM reset immediately after battery replacement, but it didn't help.
2. Testing on Safe Mode with Safari and some other tabs opened plus YT playback, almost instant macOS crash.
3. Reinstalled macOS without using Time Machine backups to get rid of any lingering issues from previous setups.
4. Removed my ethernet driver (using the Asix USB Ethernet app).
5. Minimized usage of the aforementioned apps, which seemed to help a bit, but I still experienced crashes when using Evernote with a background YouTube video in Safari.
6. Tried turning off Wifi and BT (one at a time and both together) using the ethernet adapter to maintain Internet connection, but it didn't resolve the issue.
7. Another user on a macrumors forum suggested that having another administrative account active somewhat might help, but it didn't make a difference for me.
8. Attempted to kill the configd process, but it immediately auto restarts, causing further issues with macOS.
9. Reduced peripherals such as my MX Keys keyboard and mouse (since my trackpad is faulty, likely due to the previous battery, and the stock Apple keyboard works fine for about 8 seconds then it stops registering any inputs for 1 second and repeats this behavior).
10. Removed my Ugreen dongle to rule out hardware issues, but it didn't fix the problem.
11. Someone else in the macrumors forum mentioned that disabling IPv6 support could help, but I couldn't do it with my Ethernet adapter, then I disabled it for Wifi, it didn't resolve the problem.

I may be forgetting some workarounds or best practices, but these are the most prominent ones that come to mind.

Here is some information about my new battery:

Model Information:

Manufacturer: SMP

Device Name: bq20z451

Pack Lot Code: 3230

PCB Lot Code: 3230

Firmware Version: 2d31

Hardware Revision: 322d

Cell Revision: 3036

Charge Information:

Fully Charged: Yes

Charging: No

Full Charge Capacity (mAh): 8500

State of Charge (%): 100

Health Information:

Cycle Count: 18

Condition: Normal

I've also included my last kernel panic report for reference.

What are your thoughts? Could this issue be related to old software and hardware, or could it be linked to my hardware or the new battery itself?

This is the most bizarre issue I've faced with my Mac so far, and as I mentioned earlier, it's possible that this problem has been present for a while because I used it plugged in for so long, both for me and others.