What is felony battery vs misdemeanor battery?

Three tiers worth distinguishing.

Simple battery is a first-degree misdemeanor — intentional touching or striking against the person's will, or intentionally causing bodily harm. No injury required.

Felony battery is a third-degree felony, where the battery causes great bodily harm, permanent disability, or permanent disfigurement. There's also a separate provision making a second or subsequent battery a felony based on a prior battery conviction, which catches people who assume a misdemeanor stays a misdemeanor.

Aggravated battery is a second-degree felony, involving intentional infliction of great bodily harm or use of a deadly weapon.

The distinction between felony battery and aggravated battery turns partly on intent — whether the great bodily harm was intended or resulted.

Where these cases are fought: whether the injuries meet the great bodily harm standard, whether the prior conviction qualifies for enhancement, and whether the force was justified.