The 1 Thing Apple Watch Users Will Likely Focus On

Apple Inc. AAPL didn't surpass any industry standard concerning battery life for its new watch lineup, and an analyst predicted Tuesday the issue will get lots of attention.

Apple said users will typically get 18 hours of use between charges. But the battery dies after just three hours of phone conversation.

"We expect a lot of focus on battery life in reviews" of the new product, JP Morgan's Rod Hall said.

The company's 18-hour estimate is based on 90 time checks, 90 notifications, 45 minutes of app use, and a 30-minute workout with music playback from Apple Watch via Bluetooth, over the course of 18 hours.

Used solely as a watch, the battery can power the device for up to 72 hours.

Hall, who believes Apples battery duration estimates are conservative, was generally positive on the device.

But Hall shaved his 2016 earnings estimate for Apple by 1.5 percent to $10.34 a share, because of lower-than expected pricing on the devices.

Analysts on average expect 2016 earnings of $9.24 a share.

Hall maintained a Buy rating and $145 target on Apple; the company changed hands recently at $125.38, down $1.76.