I have a 16in M1 Max with 64gb and 2tb SSD which I purchased in December 2021. A few months ago it started exhibiting the issue of beeping and the flashing orange light on the MagSafe 3 connector intermittently whilst charging (3 beeps with the flashing light, then it stops for a second and then repeats more often than not). The screen also flashes and a battery not charging warning message appears; after adding the battery status icon to the menu bar. I tried over a period of time all of the battery settings i.e. Optimized Battery Charging, Low & High Power Modes but these did not help. My battery health status displays as Normal at 90% of maximum capacity.
As an aside, my previous MacBook Pro had battery issues; swelling which stopped the trackpad from working. The keyboard also had issues (I now always use a Magic keyboard and mouse), so I was already accustomed to problems of this nature with Apple products. I recently refurbished my old Macbook Pro with new keyboard and battery, so have seen how the Chinese put these things together. Changing the battery and keyboard are not for the faint hearted.
Since I use the machine for up to 12 or more hours a day, leaving it unplugged for any extended length of time is not really an option. Due to the nature of my work, I quickly drain the battery, so having to put up with constant noise is most annoying when it was plugged in. Sometimes I can use the machine for a day or so without an issue and then it starts up again, sometimes with the battery at a critical level before it would start charging properly again.
I booked an appointment at my local Apple Store and although they ran every diagnostic no faults were found. I managed to escalate my case with Apple Support and was told that I needed to wipe the machine and reinstall Ventura. I have worked in the IT industry for over 40 years, so I knew that the chances of this being the cause was remote. The MagSafe light continues flashing even when the machine is shutdown. Again this is intermittent. I even purchased a new UPS to see if there was an issue with the power supply, to no avail.
My next step was to try a USB-C charging cable so I purchased a 240W USB-C charging cable (PD 3.1) from Amazon which supports 140W (the wattage of the standard charger for this MacBook Pro) as well as 100W (PD 3.0). This appears to have solved the issue, although I have only been using it for a few days. It is also worth noting that the reason for the return of the MagSafe port (I believe) is for the faster charging capability it offers (@ 140W) that was not at the time available via the USB-C/Thunderbolt 4 ports (@ 100W).
If the new USB-C cable has solved the issue then there could be an intermittent hardware fault such as with the MagSafe 3 cable (the same charger appears to work fine with a USB-C cable) or the MagSafe port. Of course it could also be the batteries that Apple use which have a smart charging capability. If indeed the USB-C port is only PD3.0 then the power being pushed to the battery is lower than via the MagSafe 3 port. Could it be the fast charging capability of the MagSafe port that has been compromised?
