My macbook pro 2017 isn't lasting more than 2 hours.

Hi,

Try to check your battery condition with Apple Diagnostics if it reports battery related error.

Use Apple Diagnostics to test your Mac - Apple Support

If it doesn't help or error is reported, you should contact Apple Support or take your MacBook Pro to your local retail AppleStore, Genius Bar or Apple Authorized Service Provider to be examined your MacBook battery condition.

Official Apple Support

Genius Bar Reservation and Apple Support Options - Apple

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Mac Repair & Service - Apple Support

It is likely you need a new battery.

Get help with your Mac laptop battery - Apple Support

Batteries are a wear item, like the soles of your shoes and the tires on your car. Their expected lifetime depends on use (as reflected in Charge cycles) and also in the passage of time, used or not. After a while, you should expect to have to replace the battery.

Battery life also depends on two factors you may be able to control a bit better. Lithium polymer batteries deteriorate when they get too hot, and when they are subject to very deep discharge. These should be avoided when possible.

Despite using these batteries in millions of Apple devices, there is still a lot of of randomness in exactly which battery will fail when.

Apple SUGGESTS (but does not Warrant) that your battery MAY last as long as 1000 charge cycles, provided all other factors are well-controlled.

Apple uses the criterion that a battery that doesn't to hold 80 percent of its original charge capacity should be serviced, and likely replaced.

When designing systems, that 80 percent rule is intended so that, over a Very large sample of devices, almost all will be able to achieve their 'mission' -- still have at least 80 percent capacity at the three-year mark.

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When you present your Mac at the Genius Bar with a battery complaint, the technician will perform some diagnostic tests on the battery, looking for hidden faults. If your battery passes all those, the question the technician will ask is "is this battery still able to deliver 80 percent of its original capacity TODAY."

If it is, that battery is working as intended and will not be replaced.

When your battery can no longer can perform as expected, you will need to replace it. Batteries wear out. Their levels decrease with time.

Batteries - Maximizing Performance - Apple

Batteries - Maximizing Performance - Apple

A common user-induced cause of shortened battery runtime is the presence of unneeded anti-virus and so-called "cleaning" apps. It is common to see some reducing runtimes to as low as 2-3 hours, even on computers with healthy batteries. Have you installed any of that uselessness?

Since the dawn of macOS X over 20 years ago, it has featured elegant, built-in self-maintenance routines that run automatically in the wee hours of the morning. They do ALL the housekeeping, including any defragging needed. Trash apps interfere with the elegance you paid Apple to build into the operating system and can cause serious performance issues, including instability.

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. 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 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 AC power when it is possible to do so, and only run on batteries (which could be somewhat slower) when no AC sources are at hand. Your Mac will NEVER over-charge.