PLMEN underwater drone 25.2V 100Wh IP68 waterproof battery 

Custom a waterproof battery will need to provide the following requirements details:

1.Battery voltage (V)
2.Battery  capacity(Ah)
3.Battery charge and discharge current.(A)
4.Battery usage:
5.Battery connector:
6.Battery size:
7.Battery waterproof level: (IP65 ,IP67,IP68)
8.Battery working environment.
Then PLMEN will design a suitable battery for your project.