One user analyzed how the new AirPods and their case actually charge, revealing a bunch of interesting details about charge times, trickle charging, boost charging and so forth.

For the purposes of this test, as first noted by The Loop’s Dave Mark, Reddit user “colinstalter” was charging his second-generation AirPods and the regular charging case, not the Qi wireless counterpart, with a standard 5-watt brick and a standard cable. He then recorded the battery percentages at various times using the Battery widget on iPhone.

Here are his key takeaways:

  • The AirPods “boost” charge for the first 3.5 minutes at 2.35 watts (0.46A / 5.1V)
  • The earbuds take 30 minutes to completely charge from dead
  • The charging case + dead AirPods take two hours to fully charge
  • The charging case waits to charge until the earbuds hit 20 percent
  • AirPods + the charging case never draw more than 2.5 watts total

The charging case probably waits to charge itself until AirPods hit 20 percent because it needs to communicate with the earbuds (if you have AirPods, you may have noticed that sound quality and connection reliability tends to take a hit when they drop to 20 percent, especially when you hear the second audible warning marking 10 percent charge).

“The logic just prioritizes juicing up the AirPods first,” the poster commented. “I’m assuming there is a thermal limit, but I was surprised it doesn’t at least draw 5 watts and charge both.”

Another interesting observation: the case draws extra power from the charger for about 3-4 minutes every time you open the lid. One possible explanation is that the case is in low power mode when closed, but ramps up when opened.

The AirPods case battery

And when your AirPods hit 20 percent, the case then trickle-charges until the buds hit 90 percent. If you’re juicing up just the charging case with no earbuds in it, it will “boost” charge for the first 10 minutes before settling at around 1.43 watts.

A teardown analyst of the new AirPods revealed that the case holds 1,520 mWh while each earbud holds 93 mWh, for a total of 1.706 mWh. You can use a more powerful charger but that won’t help you much because AirPods and their case will never draw more power than needed.