MBP suddenly switching off and losing time

[iDron]

Hi there, wondering if someone recongnizes this problem:

For about a week, my 2015 MBP often immediately shuts of with supposedly 80% battery remaining. Once I plug in the cable, it reboots but often sets the time back to 1/1/2020 8:00am. I reset PRAM and SMC. Checked the battery status with coconutBattery, has about 31% capacity, which is really low, even though the cycles are only at 644. Also did the hardware test, and it shows no faults.
Can it be anything else than the battery? Once it's connected to power, it seems fine. About 3 years ago, it had some water spillage. Brought it to the Apple Store to clean. They said it's working now but components might start to fail in the long term. Also, it has been dropped once from about coffee table height. So, besides the battery being degraded, their might have been some damage over the years.

Any suggestions for a solution? Did not really plan to buy a new MacBook now, and wonder if a battery replacement is worth it if the device itself might not live that long anymore.

 

[Fishrrman]

If it was me...
... I'd take it to a brick-n-mortar Apple Store and get the battery replaced.

The cost should be $199 including parts and labor.
That's A BARGAIN for what you get in return.

If you DON'T HAVE an Apple Store nearby, you could try calling Apple support.
DO NOT CALL A THIRD-PARTY PROVIDER!
Call APPLE.
Explain the problem and they may be willing to send you a prepaid shipping box so you can return it to one of their facilities for repair.

 

[hobowankenobi]

Have you ever calibrated the battery? While I agree, it is time to replace it...if properly calibrated, you would get a better idea of how fast it is discharging.

As to the question....could it be something else: If you don't see any issues when plugged into power, a very good chance it is battery only. If it DOES behave oddly while connected to power, that would complicate diagnosis.

 

[iDron]

Thanks for your replies guys! Was thinking if it’s worth replacing the battery or just getting a new M1 MacBook.

Now decided to get the battery replaced. Went into the Apple Store today and they told me this means a Top Case replacement (So including the case, keyboard, trackpad). This is actually good news, as the case has some dents and the keyboard is full of dust and debris.

My old MacBook does all I need, is still fast enough in most daily use cases. So I hope it’ll gain like 2-3 years of life with this battery and top case replacement. The M1 laptops might also have some issues as being the first Apple Silicon generation, or we might see a 14inch MBP very soon. So, hope my old MacBook will still carry me a few years till that time arrives!

 

[iDron]

Just got my Macbook back. Surprised how clean a keyboard can look 😅

All in all very good service. My MBP has a German keyboard, but I'm based in HK at the moment. Took them 2 days to get the german keyboard topcase. Dropped my Macbook off Friday evening after work and picked it up Monday morning.

The keyboard illumination needed a SMC reset, but now it all seems to work properly.

The battery seems to be already 1.5 years old, but 0 cycles and over 100% capacity, so I assume that's good.

 

[Ruggy]

Good it's working but your problem is typical of the other battery in the MBP just in case someone else has this.
They all have a cell battery known as a PRAM battery, usually something like a CR2032 to keep the settings for the bios when it's off power and typically, when they start to die your clock starts to go wrong and then when you power up the date is reset to whatever the default it. Sometimes it'll have trouble finding the HD or keyboard but maybe not with a MBP.
They do need changing eventually in all computers and it's almost certainly what was wrong with yours.
Sorry I didn't see your post to tell you earlier.

 

[iDron]

Good it's working but your problem is typical of the other battery in the MBP just in case someone else has this.
They all have a cell battery known as a PRAM battery, usually something like a CR2032 to keep the settings for the bios when it's off power and typically, when they start to die your clock starts to go wrong and then when you power up the date is reset to whatever the default it. Sometimes it'll have trouble finding the HD or keyboard but maybe not with a MBP.
They do need changing eventually in all computers and it's almost certainly what was wrong with yours.
Sorry I didn't see your post to tell you earlier.

Are you sure they still have these in recent Macbooks? I read somewhere that Apple phased them out. Meaning that they expect the main battery to keep a last bit of power for quite a while. But once the battery is really dead, this issue happens everytime the battery is empty.

 

[hobowankenobi]

Are you sure they still have these in recent Macbooks? I read somewhere that Apple phased them out. Meaning that they expect the main battery to keep a last bit of power for quite a while. But once the battery is really dead, this issue happens everytime the battery is empty.

You are correct. No secondary battery in Macs for years. No BIOS (technically) either.