The current generation of batteries are dumb and I think they could be far more efficient! A battery in your computer, phone, tablet, etc is a solo element that is charged when you plug in your device. Charging a battery when it is not empty can harm it’s capacity and therefor battery live.
My idea: Split the battery in multiple blocks. Every block can only be charged when it’s empty. Blocks that are full are not charged or used. When you device is connected it takes it’s power directly from the wire to the device. When the device is not connected only one block is used to give it’s power, the others are sleeping.
For example, If we split the battery in 10 blocks the worst case scenario will be that your device cannot charge for more that 91% (because one block is almost empty, but not empty enough to be charged, let’s assume that less than 10% is chargeable).
I’m no expert at batteries but I think this simple idea can make your battery live longer and that would be good for you and the environment. But maybe I’m thinking to simple :p