Charging 16" Macbook Pro with Apple 87W USB-C Power Adapter

It should be fine. The computer will draw as much current as it needs, taking into consideration the capabilities (stored in a "marker" IC) of the cable. You should have no problems using almost anything, although it could be painfully slow trying to charge it with a 1A iPhone power adapter or something similar.

It should be fine in the vast majority of cases, unless the OP regularly games or does other activities that need a very hihg power draw for extended periods. Some of the more technical websites have reviewed the 16" and provided graphs of power draw and show that 96W is rarely reached, and when it is, it is rarely sustained. Thus 87W should be fine for most use cases to both charge and sustain power, but it probably won't charge quite as quickly as it would with the 96W.

Joshua Morganstein wrote:

I've been using an 87W adapter for several hours with my 16" and, as to be expected, it appears to work reasonably well charging the battery, though I assume a bit less swiftly than I could expect from a 96W adapter. If I had the 16" under heavy load, I also imagine it's possible that the 87W adapter wouldn't be able to supply enough power to keep the battery from being drained, though probably very slowly. However, I anticipate that would likely be under not just a heavy load, but one that is sustained for an extended period of time as the 87W adapter is supplying a fair amount of charge at all times. Based on all the constructive feedback on this thread and from what I've read elsewhere, it's my understanding that using a lower wattage rated adapter to charge a MacBook Pro internal battery does not increase the risk of any acute damage to the battery or computer, nor does it alter the life expectancy of the battery, which is largely impacted by charge cycles.

Any modern notebook computer needing more than 87W continuously would well on its way to thermal shutdown.

That being said, it well overthinking it that the 9W is going to make much of a difference. It's easy enough to monitor the power usage via System Report, coconutBattery, or other tools, and I'd be surprised if it's more than half of the provided power adapter output for most uses.

No it will not damage your computer or internal battery. You can use it with confidence.

yelad wrote:

No it will not damage your computer or internal battery. You can use it with confidence.

Yes he can use it and be confident that it will not provide enough power.

I have multiple adapters in different locations throughout my home and work spaces at which I previously charged a 15" that I just replaced with a 16". If I just did what was "recommended" I'd be spending about $400 just buying new 96W power adapters to replace all my 87W power adapters and left with five 87W power adapters I'd need to spend time and energy selling or otherwise finding a use for. So, a fair amount of money and time.

I appreciate the OPs question about simply using existing adapters (for the potential savings of time, money, and resources), and the thoughtful responses offered by some here to help those less knowledgable consider the pros and cons of various options.

I've been using an 87W adapter for several hours with my 16" and, as to be expected, it appears to work reasonably well charging the battery, though I assume a bit less swiftly than I could expect from a 96W adapter. If I had the 16" under heavy load, I also imagine it's possible that the 87W adapter wouldn't be able to supply enough power to keep the battery from being drained, though probably very slowly. However, I anticipate that would likely be under not just a heavy load, but one that is sustained for an extended period of time as the 87W adapter is supplying a fair amount of charge at all times. Based on all the constructive feedback on this thread and from what I've read elsewhere, it's my understanding that using a lower wattage rated adapter to charge a MacBook Pro internal battery does not increase the risk of any acute damage to the battery or computer, nor does it alter the life expectancy of the battery, which is largely impacted by charge cycles.

If anyone has done or is aware of any testing that has been done to indicate my above understanding is incorrect, I would welcome any resource/links to learn more so I can better understand this issue.

From the link I provided:

"You can use a compatible higher wattage power adapter without issue, but

it won't make your computer charge faster or operate differently. If

you use a power adapter that is lower in wattage than the adapter that

came with your Mac, it won't provide enough power to your computer."

Your battery will not be damaged.

Joshua Morganstein wrote:

Then you are indicating it is unnecessary to use the 96W adapter over an 87W adapter?

Not strictly necessary. I mean - I wouldn't go out of my way if have a different power adapter available that will do the trick. It's not much different than whether or not one uses an iPhone 5W cube because it's available compared to a 12W adapter. It might be slower but there's nothing that's going cause damage or even cause undesirable operation. It will just charge slower.

Drawing power more than the rating of a charger will cause it to heat up faster and more so than the proper rated charger. Though 87W vs 96W may not be too much of a difference but a 60W will surely not work with the 16” MBP. Also some non original chargers rated at the proper rating do not really work and will not charge your MBP properly, this happened to me and I ended up buying 2 original 87W.

i will be waiting for the new MBP 16 to arrive and will test if the 3 87W I already have will work with, I am almost sure they will with no problems.

Find the right power adapter and cable for your Mac notebook - Apple Support

Mr_Shmelo wrote:

Hi,

I recently bought the new 16" Macbook Pro. Can I use my 15" charger (Apple 87W USB-C Power Adapter ) to charge my new Macbook? Can it damage my battery?

Well you can, but why—not recommended.

Use the 96 W charger that came with your new Mac.

On those non-original chargers the MBP showed it was charging but was actually discharging much faster than it was charging, which caused my MBP to turn off suddenly with zero power! I took my MBP to Apple service twice and called in and did so many tests and resets, nothing resolved the mysterious shutdown with zero power except realizing (after a while) that the charger was weak and useless. Using the original charger resolved my issue and is still working fine in my MBP 15” 2018 model almost two years later.

Then you are indicating it is unnecessary to use the 96W adapter over an 87W adapter?