Achieving rapid charging in quantum batteries requires the efficient harnessing of quantum resources, which is a task with great challenge experimentally. Here we propose and experimentally realize a quantum battery charging protocol that enables fast injection of substantial energy using a trapped-ion platform governed by the quantum Rabi model (QRM). The core of the protocol lies in the employment of the squeezing effect and the QRM criticality. Reinforcement learning further improves the charging performance by optimizing the preparation of the squeezed and anti-squeezed states and accelerating energy inflow near criticality. Experimental implementation with a single ${}^{171}\mathrm{Yb}^+$ ion demonstrates the feasibility of the protocol, where the vibrational mode (i.e., quantized phonons) acts as the quantum battery. We witness that both the maximally extractable work (i.e., ergotropy) and the charging power exhibit criticality-induced enhancement. This work provides a practical pathway toward criticality-enhanced quantum batteries, underscoring the potential of squeezing-mediated amplification and displacement-based energy storage in realistic quantum systems.