Embodiments of the present disclosure describe systems, methods, apparatuses for wirelessly charging handheld and consumer electronics in wireless power delivery environments. In some embodiments, techniques are described for retrofitting wireless power receivers into existing devices e.g., through wirelessly powered battery apparatuses. For example, the apparatuses discussed herein allow any device that accepts standard form factor batteries to be transformed into a wirelessly powered device. The wirelessly rechargeable battery apparatuses can be applied to any battery form factor including custom or semi-custom battery form factors for mobile phones, laptops, tablet computers, etc. Advantageously, among other benefits, the apparatuses discussed herein overcome the product integration challenges discussed above.