The Apple Watch Series 5 features is expected to address a number of health issues including heart problems, stress and even sleep concerns like sleep apnea.

Most of these features are definitely groundbreaking and is a testament to Apple’s dedication to focus on helping Apple Watch owners keep track of their health. What we’re hearing so far is quite exciting and seems legit based on new patents announced by the U.S. Patent and Trademark Office.

Complementing the ECG and atrial fibrillation detection features, analysts expect other health functions such as sleep tracking, smell detection and even a function to measure blood sugar levels. If true, these features can definitely help Apple Watch users who are stressed out, have sleep pattern problems or those struggling with diabetes.

But herein lies the problem. Will all these health benefits, one would expect that the Cupertino giant will also improve on other aspects of the watch, particularly its battery life. The Apple Watch Series 4 is already impressive with an average of 18 hours of battery life on normal use (which includes the ECG function). But with the new, more complex features, Apple might need more juice to power up its wearable tech.

Sleep tracking, in particular, would most likely require the user to wear the Apple Watch even while sleeping. This could seriously undermine any chance of charging even if it’s rumored that the next watch can do wireless charging via the new iPhone.

One plausible way to address this is to make the Apple Watch solar powered, an idea that’s been broached already back in 2014. According to Inverse, an improved battery could help replenish an Apple Watch and require less for the user to take off the device.

Back in 2014, the New York Times reported that the Cupertino company is already playing with the idea of incorporating a solar-charging layer to the Apple Watch.

This option is not new as some wearable tech such as Citizen Eco-Drive can actually run a watch for six months in the dark as long as the solar charge is full. Of course, the Apple Watch is a more complex device, so solar might not work as well as the Eco-Drive watch but it can be a good start.

And then there are the other options like the Wi-Charge, which can basically charge a phone with up to 10 watts of power using infrared beams even if the user is wearing the watch.

Apart from battery improvements, we can’t wait what other upgrades Apple would apply to make the Series 5 a coveted health device.