how long should it take an iMac to power up?

• According to the Apple website, if the battery is at roughly 50% charge, it should take about 1 hour to reach 80% charge, with another 2 hours for trickle charging to reach full charge. It will take 2 hours to fully charge the battery if you charge it at 80% capacity.
• A MacBook Pro will work without a battery, although at a decreased speed. Because the charger's maximum power input is less than the computer's maximum power consumption under high load, it will automatically restrict performance.

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