Nope. Marge blocks transmit power so it will fully charge as long as there is power coming from the ship. That being said there is no preset for power conservation unless otherwise set up. So if there is no way to recharge the batteries they will deplete as the ship uses up power.

That all being said, The likelihood of the missile running out of power before being used is very slim indeed. The fuel on the missiles will run out long before the batteries will when deployed.

I'm impressed with how compact it is. Will the battery die if it spends too long attached to a ship?