The Black Shark 3 got its battery details confirmed ahead of its March 3 announcement. The company posted another official teaser confirming the battery capacity and charging speed.
The Black Shark 3 was rumored to pack a 5,000 mAh battery with 65W fast charging support. The rumors got the charging speed right, but Black Shark's official teaser now says the battery capacity will actually be 4,720 mAh.
More features of the Black Shark 3 are likely to be officially confirmed in the days leading to the unveiling.
I've got the Black Shark 2, I've had 8-10 updates since I bought it, battery drain is due to extra features like DSP display enhancement which you can switch off to increase battery life.
Or you can just replace the battery from service center, those are pretty cheap.