According the latest in a string of scoops from 9to5Mac, battery life has been a pressing concern for Apple throughout the development of the Apple Watch. And for the first time, "sources familiar with the Watch's development" have provided some early figures on what consumers can expect when the device ships sometime this year. In short, Apple Watch will exhibit similar longevity to what we've seen from many Android Wear devices on the market today.

Apple was originally shooting to eke out an entire day of battery life from Apple Watch. Obviously that's not all active use; in fact, the company is said to be shooting for 2.5 to 4 hours of active application use with the screen turned on. That'll vary depending on how heavily you use it, of course. But since the wearable's display will often be turned off throughout the day — and because the iPhone handles a lot of computing tasks — Apple is apparently hopeful that the watch can make it from morning until you place it back on the wireless charger at night. 19 hours of combined active and passive use seems to be the bar as of right now.

There's only so much that can be done to extend a smartwatch's battery life

This isn't unlike what you'd get from the current field of Android smartwatches; use them constantly and they won't last a day. But that changes with more average use. Notably, the Pebble smartwatch continues to blow away the field in terms of battery life, but it's a very different device when compared against a Moto 360 or the Apple Watch. In standby and low-power modes, 9to5Mac's sources say Apple Watch can last through two or three days. And if for some reason you want to use it strictly as a timepiece and leave the screen on at all times, it'll die out after three or so hours. Using it as a workout companion? Your gym routine shouldn't last more than four hours.

Apple is reportedly testing Apple Watch's battery life aggressively — and in large numbers. 9to5Mac claims the company has distributed over 3,000 units as the development process continues. And while the iPhone is a critical companion to Apple Watch, the device itself may be more powerful than some expected. 9to5Mac says the CPU inside is more or less equally as powerful as the A5 chip that powered the iPhone 4S and iPad 2, and remains in the current-generation iPod touch. Considering the tiny form factor, we're expecting the same fluidity and responsiveness that have become hallmarks of iOS. But as for the battery, Apple can only do so much. The simple fact is that battery technology doesn't evolve at nearly the same rate as the smartphones in our pockets and wearables on our wrists. The company will undoubtedly keep pushing for improvements as Apple Watch's launch nears; it's expected to ship beginning in March.