When the Apple Watch Series 6 launches later this year, it will likely have an upgraded battery.

The news comes from Twitter user @yabhishekhd, who shared an Apple battery that just passed the certification process at the Korea Testing and Research Institute. The model number of this battery is A2327 and has a capacity of 303.8 mAh. However, the other two leaked batteries have a smaller capacity than the Apple Watch 5.

How can we be sure that this battery is intended for the Apple Watch and not, say, an AirPod charging case? We don't know for sure, but looking at the Apple Watch Series 5 battery in the photo below the iFixIt teardown, it certainly looks similar.

So if this is indeed for the Apple Watch Series 6, what does it really look like: it's just an 8mAh increase over the Apple Watch Series 5's 296 mAh cell. In other words, a capacity increase of just under 3%. What do you think?

Of course, there are limits to what you can do without walking around with a computer on your wrist, and the history of the Apple Watch is built around these small improvements. After all, this is a 9% increase from the 279 mAh battery in the Apple Watch Series 3.

And while this battery enhancement is not expected to boost the "up to 18 hours" that Apple is promising with the current model, it should at least ensure that the new features do not affect stamina. In other words, a slight improvement in battery capacity may allow the Apple Watch 6 to "stand still" on current supplies despite the additional features.

According to MySmartPrice, there are two other batteries with model numbers A2345 and A2306, with capacities as low as 265.9 mAh and 262.9 mAh; as AppleInsider speculates, these capacity differences could be due to the different sizes of Apple Watch 6 models, or possibly for models with LTE connectivity.

In addition to the usual performance improvements, Apple Watch 6 rumors point to the addition of SpO2 monitoring (blood oxygenation), improved water resistance, and wellness features such as yoga and stress detection.

There is also continued talk about sleep tracking, which is indeed built into WatchOS 7, but it is possible that Apple Watch 6 will offer enhancements to this. For example, the device is rumored to have a Micro LED display, which is more efficient than the OLED screen on the current Apple Watch. Thus, the Apple Watch 6 could be worn all night and never run out of charge, and could be recharged in the morning.

We shouldn't have to wait too long to learn what Apple is preparing for the Apple Watch 6, but it may be a little longer than usual. The company usually does its showcase in September, but Apple has said this time that the iPhone 12 will be delayed a few weeks. Along with the new iPhone 12 and Apple Watch 6, we expect to get a glimpse of the new AirPods Studio.