Looking at lists of best cell phone battery durations, the longest-lasting players have one thing in common: huge batteries. In many cases, however, these batteries result in larger form factors and heavier weights. For some cell phone users, it is worth the trade-off if it means the device lasts as long as possible.

Xiaomi engineers are working on new battery technology that aims to extend battery life in the same volume.

According to PhoneArena, Xiaomi announced via Weibo that it has developed a new smartphone battery technology that extends battery life by 10% in the same size pack. Xiaomi has achieved this in a novel way. Instead of pushing for a revolutionary way to store more energy in lithium-ion cells, the company has shrunk the control circuitry to make room for more batteries. What this means is that 4,400 mAh can now fit in the space of a 4,000 mAh battery pack.

A smartphone battery is not just a lithium-ion pack. It also incorporates connectors for the motherboard and a board to regulate the power. Think of the circuit board as the brain of the battery. They protect the battery from overcharging, overdischarging, and overdischarging, preventing long-term battery life loss. Xiaomi was able to find a way to condense these technologies so that more materials could be packed in. It is reasonable to assume that other cell phone manufacturers will attempt to do the same.

Now, 10% may not seem like a significant jump in battery life, but it is still a significant amount. In the case of the Samsung Galaxy S21, this means an additional hour of battery life.

Aside from the more cramped circuitry, Xiaomi also announced what it calls a "fuel gauge chip"; like the adaptive charging found in the Galaxy S21 and Google Pixel 6, this could use AI to learn the charging habits of the user. For example, it could slowly charge the battery to 80% overnight while the user sleeps, and then charge at 100% for the last hour. Keeping the battery at 100% all the time could be detrimental to overall health.

Unfortunately, this technology is unlikely to be included in the upcoming Xiaomi 12, whose camera array was recently leaked. Expect to see such a high-density, smart battery in Xiaomi's flagship models in the not-too-distant future.