The Apple Watch’s battery life continues to be a hot topic since the company finally released how long it’s supposed to last. Under average usage (whatever that means), Apple management said it should last about 18 hours.

Apple Watch Battery Life: How Long Will It Last?

The “average” Apple Watch user

However, the battery life could be as little as three hours for some users or even as long as five days for others. With such a large variance in the Apple Watch’s battery life, how are consumers supposed to gauge how long the battery might last for them? Of course it all has to do with how much you use it and what you use it for.

According to Natasha Lomas of TechCrunch, the 18-hour battery life quoted by Apple management assumes “90 time checks, 90 notifications, 45 minutes of app use and a 30-minute workout with music playback from Apple Watch via Bluetooth.” So using the watch any more or less than that will cause the battery life to vary greatly.

Extreme-use cases for the Apple Watch

For those who only use their Apple Watch to check the time, the battery life could be as long as five days, reports Chris Smith of BGR. Of course that kind of defeats the purpose of even having a smartwatch in the first place—especially one that costs as much as Apple’s does—but to each their own.

At the other extreme, we have the power users who will use their Apple Watch for everything, including taking phone calls. According to TechCrunch, taking calls on the watch will cut its battery life down to three hours. Playing music on the watch a lot can reduce it to six-and-a-half hours, and keeping the heart rate sensor turned on during a workout could reduce the Apple Watch’s battery life to about seven hours.

Squeezing the most out of the Apple Watch’s battery life

The good news for power users of the watch is that once the battery falls to a certain power level, the watch will kick into a power reserve mode, according to BGR. The mode enables the wearer to still be able to check the time for up to 72 hours from when the watch goes into power reserve mode.

Each time check only lasts four seconds, however.

Apple Watch battery can be replaced

One of the initial concerns about the Apple Watch was that it would become obsolete in a few years because the battery couldn’t be replaced. It’s a nightmare to change the battery in Apple’s other mobile products, so consumers were right to be concerned about whether the Apple Watch’s battery could be changed.

As it turns out, the battery can be changed, according to TechCrunch. A spokesperson for Apple reportedly told the website that the battery should last about three years. The battery can be replaced, although it is still a pain to have it changed, as it must be sent to Apple or taken to an Apple retail store to be replaced. Also it’s still unclear how much Apple will charge to replace that battery in its smartwatch.