California Penal Code Section 242 makes it illegal to use willful and unlawful force on another person. Under California Penal Code Section 243(d) PC, it is illegal to commit any battery that causes serious bodily injury to another.Los Angeles criminal defense lawyer explains assault and battery laws under California Penal Code 240 and 242 PC, penalties, and how to fight the charges. If you are a first-time offender facing prosecution for battery in Los Angeles, call our talented and professional defense attorneys today at 877-4-NO-JAIL. California Penal Code § 242 PC defines the crime of simple battery as the "willful and unlawful use of force or violence" on another person. What's the difference between assault and battery in California? Find out more about first-time assault and battery charges in the state. Physical confrontations can lead to serious criminal charges for violent crimes. California Assault With A Deadly Weapon law under Penal Code Section 245(a)(1) explained in detail. Understanding Laws, Penalties, and Defenses Related to Assault or Battery Charges.