I am in charge of the electrical systems
I am responsible for the electrical systems.
(These expressions are parallel in this situation but not all situations)
Other meanings of “charge”Â
1. The bull charged and we had to jump the fence to escape.
2. When was the charge of the light brigade? (talking about history)
3. How much did he charge you? (at the shop)
4. What are the charges and fees? (at the bank)