In order to function, hearing aids require a specific type of battery. They are one of the most important components of the device and are closely connected to its performance and the quality of the received sound. To choose the right kind of battery for your hearing aid, it is necessary to consider the specific type and model of the device and the desired lifetime of the battery. There is a constant competition between the companies producing and selling hearing aid batteries to come up with a new, better model that works for longer hours and provides better performance than the other models available on the market. Furthermore, in recent years both scientists and manufacturers have worked extensively to find a way to invent mercury free batteries that are not only environmentally friendly but also offer high-energy capacity and performance. One of the companies on the market that offers batteries covering all of the above-mentioned requirements is Rayovac. Their mercury free batteries, which are considered a top choice of many professional audiologists, are now also part of Hearing Direct catalogue of high quality hearing aid batteries. Mercury, in the form of mercury oxide, has always played an important role in the production of batteries, because it provides a longer shelf life and optimizes the hours of performance. There have been concerns that the mercury free batteries would have a shorter life cycle and would not be able to meet the growing demand of both the users and modern hearing aids. For several years, Rayovac has put a lot of effort in the invention of a competitive technology that would successfully replace the use of mercury and yet guarantee that the batteries will have a stable, long enough performance. In 2011, as a response to the constantly growing demand for environmentally friendly batteries with proven reliability and lifespan, the company introduced its next-generation product, whose production included the use of an "Advanced Voltage Agent" (AVA). The new batteries quickly became the most recognizable, powerful and longest lasting mercury free product available on the market, showing up to 30% increased performance in comparison to similar mercury free hearing aid batteries. Other useful benefits of the product include: The cell's design enables higher voltage and capacity levels and provides significant protection against leakage and corrosion The package's design allows the smooth removal of the batteries and is convenient and easy to use Rayovac's products are environmentally friendly on all possible levels - the package is made of recycled or recyclable materials So far, Rayovac has received several awards recognizing their work and success in the development of a new generation of hearing aid batteries, including the Queen's Award for Enterprise in the Innovation category. There are indications that the mercury free technology will become more and more popular in the future and will further develop in terms of quality, performance and availability.