Electrical energy is changed to chemical energy in batteries when they are charged from solar panels during the daytime and electrical power is delivered to the load when the batteries are discharged during the nighttime to power the LED sign.
(Electrical energy; is changed; to chemical energy; T:when they are charged from solar panels during the daytime and electrical power is delivered to the load) (they; are charged; from solar panels; T:during the daytime and electrical power is delivered to the load) (the daytime and electrical power; is delivered; to the load) (the batteries; are discharged; T:during the nighttime; to power the LED sign)
Electrical energy they the daytime and electrical power the batteries
is changed are charged is delivered are discharged
to chemical energy T:when they are charged from solar panels during the daytime and electrical power is delivered to the load
from solar panels T:during the daytime and electrical power is delivered to the load
to the load
T:during the nighttime to power the LED sign