The performance of lithium-ion batteries (LIBs) significantly declines in low-temperature environments, manifesting in reduced discharge capacity, diminished cycle life, and challenges with charging. To maintain optimal functionality in such conditions, preheating is often necessary. LIBs typically employ two fundamental approaches for low-temperature heating: external and internal heating mechanisms. For external heating, a Battery Thermal Management System (BTMS) is commonly utilized. This system is vital for managing the thermal conditions of the battery pack. It ensures that the temperature is evenly maintained across the entire pack, avoiding the formation of thermal hotspots and keeping the temperature within a range that supports the best possible performance and durability of the battery. Instead of relying on external sources, internal heating techniques make use of the intrinsic heat generated by the battery during its functioning, particularly while it is being charged or discharged. Compared to external heating, internal heating has several notable merits: it achieves more consistent temperature regulation, consumes less energy, and enhances the overall efficiency of the heating process. Another prominent approach to internal heating is through the utilization of Alternating current (AC) excitation. This method involves applying AC signals with specific frequency and amplitude parameters to produce thermal energy within the battery. Among diverse internal heating options, AC heating is particularly highlighted for its well-balanced relationship between energy expenditure and heating performance. Several studies have preliminarily suggested that this method is benign to the battery, given that the current excitation is precisely optimized. Importantly, AC heating does not require any modifications to the battery’s architecture, which makes it a highly desirable and extensively studied approach. It effectively enhances battery performance without jeopardizing its structural integrity. This chapter introduces the AC heating methods. Section 5.1 reviews current heating methods for LIBs in low-temperature environments, categorizing them into external heating (e.g., air, liquid, and phase change materials (PCM) preheating) and internal heating (e.g., self-heating, direct current (DC), and AC preheating). Each method is evaluated for its efficiency, energy consumption, and impact on battery performance, highlighting the trade-offs between heating speed, uniformity, and system complexity. Section 5.2 delve into the critical constraints and strategies for low-temperature AC heating of LIBs. The primary constraints identified include lithium plating, overcharge, and over-discharge, which can significantly impact battery lifespan and safety. Two new lithium plating standards for three-electrode and two-electrode full cells were developed to prevent irreversible damage during AC heating. The study highlights that the onset potential for lithium plating is still controversial, and an accurate criterion is essential for non-destructive heating strategies. Section 5.3 introduces a comprehensive framework for designing a non-destructive bidirectional pulsed current (BPC) heating strategy. The framework integrates an electro-thermal coupled model with constraints on lithium plating and terminal voltage. The BPC heating strategy is optimized to maximize heating efficiency while maintaining battery health. Experimental validations demonstrate that the proposed strategy achieves significant improvements in heating rates and minimal impact on battery capacity even after multiple heating cycles. The findings suggest that optimizing BPC parameters, such as frequency and pulse ratio, can enhance heating power, especially at higher battery states of charge (SOC). This work provides a robust solution for enhancing the low-temperature performance of LIBs, crucial for applications in electric vehicles (EVs) and energy storage systems (ESSs) in cold climates. Section 5.4 summarizes the work in this chapter.