system
Given the following post, respond as if you're commenting on Reddit:
human
If the capacity of a battery charging another battery drops below that of the receiving battery, will it stop transferring electricity since the electrons will no longer prefer to leave the lower energy "state" of the drained battery?

Is the above reverse motion of electrons to the lower-capacity battery prevented by the orientation of + and - wires, or would the partitioned layout of the cathodes and anodes prevent it? I am assuming entropy would be the main motivation for electricity stopping its flow if the above is true.
gpt
Charging stops once both reach the same voltage (at zero load). That doesn't have to happen at the same energy stored, it depends on the battery types.  Some will stay close to their maximum voltage until they are nearly empty, others will go down faster.