Rechargeable batteries offer a reusable alternative to disposable batteries that can be used repeatedly. By using a compatible charger, these batteries can be recharged many times, rather than needing to be replaced continually. This reduces the maintenance cost of upgrading these batteries. As a result, these batteries are ideal for powering high-density equipment such as keyless entry systems, digital audio players, digital cameras, GPS devices, and video game controllers. They can easily be substituted for disposable batteries since they are sized according to the same ANSI/IEC standards as disposable batteries.