The OnePlus Ace 3 Pro combines flagship performance with a 6,100mAh battery, which on paper should make for a long battery life. However, the Chinese brand may not stop there.

Longtime leaker Digital Chat Station has claimed on Weibo that OnePlus and OPPO are now working on a 7,000mAh battery. The tipster’s post also suggests it could land in a mid-range phone.

This wouldn’t be the first phone to come with a 7,000mAh battery, as we’ve seen a few mainstream phones with similarly sized batteries (such as the Samsung Galaxy F62 and Galaxy M51). We’ve even seen niche players offering chunky phones with 10,000mAh or even 20,000mAh batteries. However, these phones have all generally had thick, heavy designs. So most mainstream Android phones in the past few years have typically maxed out at 5,000mAh.

However, OnePlus recently touted a silicon-based battery as part of its so-called Glacier Battery technology in the Ace 3 Pro. Silicon-based batteries tend to be denser than traditional batteries, allowing for more capacity from a smaller battery. The Ace 3 Pro in particular is less than 9mm thick and weighs just 207 grams, so it makes sense that a phone with a 7,000mAh silicon battery wouldn’t become dramatically thicker and heavier.

OnePlus isn’t the only company using silicon-based batteries in its phones. Other players like HONOR and Xiaomi have also released phones with this technology. So your next device could have a bigger battery or the same battery capacity in a smaller form factor.