Seamoth Solar Charger

The Seamoth Solar Charging Module is an in-development upgrade that enables the player to recharge the Seamoth's battery while in the sun.

In the future, the player will be able to add this upgrade to the Seamoth by using the designated upgrade console on board of the Cyclops while the Seamoth is docked.

Speculation
It is to be assumed that the efficiency of this upgrade decreases the further the Seamoth is away from the water surface, similar to the Solar Panel.