MacBook Pro M1 shows battery X symbol and max fans after 40W charger

That computer is a battery-CAPABLE device. It is not optimized as a battery-operated device. (It is NOT an iPhone.)

Your computer performs best when connected to AC power, such as the power adapter. It can use the full output of the Power Adapter AND when doing especially challenging work will also freely "borrow" power from the battery. In some cases, even with the power adapter connected, the charged state may decline during very stressful work.

When used only on battery, your computer has no extra cushion of power, and may perform more slowly. However, for ordinary non-stressful tasks this may not be objectionable (possibly not even noticeable.)

In general, you should ALWAYS connect a power source when it is possible to do so, and only run on batteries (which could be somewhat slower) when no power sources are at hand. Modern Macs maintains optimum battery charge levels under program control, and will NEVER over-charge. Activate Battery Health Management and do not spend another moment of your time thinking about charging.

When you set it down in one place or for the night, plug it in. Then you won't CARE whether it would drain the battery when nominally asleep.

The online information you found is not up to date, and not appropriate for current Macintosh batteries. It could be hazardous to the overall health of the computer.

When you deeply discharge the battery, it can easily become confused, and may be damaged. DON'T do that!

niklas446 wrote:

After using a 40w charger, my MBP (16 inch) runs in a very weird condition. The battery had an X symbol, the fans runs at max speed and I had no information about the battery and charger under systeminformation. Since then I only charged him with USB-C and mostly with an Apple 96W charger. I found a possible solution. I followed the steps and I bought an original 140W with a magsafe 3 cable too. I played music in battery mode to drain the battery to 0%. After that I waited one day

.

Then I connected the new arrived power adapter and cable - Tada it worked!

The fan stops running on max and I see the status of my battery. I tried before the same with the 96W Adapter and USB-C. I had a similar outcome but the fans still run at max. I could see the battery information etc. . But after a reboot the problem comes back. In most forums they say it's a hardware issue like a defective logic board or battery but it's obvious not.

What was the issue ? Is there a battery management system that had a bug?

[Edited by Moderator]

" Then I connected the new arrived power adapter and cable - Tada it worked! "

I'm confused, you state the new power adapter and cable worked. Whats the question exactly...?

if you have some on going hardware issue take it in:

In or out of warranty you can get a free over the counter 'Apple Service Diagnostics' test /assessment

Make an appointment for a "hardware issue"

Genius Bar Reservation and Apple Support Options - Apple

Outside the USA

Contact Apple Support - Apple Support

If the battery icon has an "X" on it, then it means the battery is not physically seen by the system. If the battery is not seen, then it cannot charge.

A 40W power adapter won't properly charge your battery because the laptop will probably try to power on & not have enough power.....its possible it will just get stuck in this loop. If the battery remains at 0% for any length of time, it can cause permanent damage to the battery including where it may not be visible to the system. Once in a while such a battery can miraculously begin to charge again, but it is extremely rare (the battery may function relatively Ok or it may have issues & fail again).

My guess is the battery has a hardware failure. Lithium Batteries can sometimes go between a working state & a non-working state until they finally fail completely.

Another possibility is if you used a third party power adapter which may have caused hardware damage to the Logic Board's power & charging circuitry. It is unfortunately there are so many sub standard power adapters out there (best case), or counterfeits & fake one (worst case). If you decide to use a third party power adapter, only use a high quality one from a respected manufacturer. Even if you purchase a high quality brand.....many marketplace websites will have counterfeit & fakes out there that can be extremely dangerous (reviews & ratings are meaningless these days because people scam them).

You didn't specify the exact model of Mac, but I do know that there are some models (I think it was an M2 MBPro) where it seems they have a bit higher Logic Board failures with power/charging issues. I've never seen them show any issues with the battery though, just charging & powering on issues.

You can try running the Apple Diagnostics to see if any hardware issues are detected. Unfortunately the diagnostics rarely detect problems.

FYI, it is very difficult to determine the health of an Apple battery on an M-series Mac. I've had to create a custom script to retrieve the detailed battery information so I can analyze an Apple battery....usually it involves monitoring the battery information over time & hopefully finding something when the battery has an issue. Needle in a haystack. Even this is not enough, but it is the best I've found to assist in analyzing an Apple battery. I'm still trying to learn & understand it.

Hi,

Try to run Apple Diagnostics if it's caused by Hardware, battery related.

Use Apple Diagnostics to test your Mac – Apple Support (AU)