These disposable 9V lithium batteries are intended as a direct replacement for alkaline batteries of the same type. They provide approximately the same nominal voltage, along with a much denser charge for longer run times and a very long shelf life. They are also considerably lighter than their alkaline counterparts.
The battery case is the standard 9V rectangular configuration, although the case may be approximately 3mm shorter than a carbon-zinc battery case. Contacts are both top-mounted, with one female and one male contact to prevent polarity reversal. This battery style, also known as PP3, MN1604, “square” or “transistor” is commonly used in radios and smoke, fire and carbon monoxide detectors as well as musical devices, toys, radio controllers and games.
These cells are manufactured with a lithium foil anode, iron disulfide cathode and one of a few possible electrolyte types. The 9V battery may consist of multiple individual cells in the same case. Nominal voltage is typically 9.6, which is within the tolerance range of most devices. The Li/Fe (lithium/iron) construction provides a much higher charge capacity tan alkaline, providing up to 1200 mAh of energy, more than twice that of a typical alkaline 9V. The design is also highly resistant to self-discharge, allowing storage for up to 10 years.
Because of their lighter weight, these batteries are an excellent choice in applications where weight is a concern. The extremely long shelf life allows many spares to be purchased ahead of time and stored for long periods, making them ideal for storm shelter radios, etc. In use, these batteries will outlast other non-rechargeable batteries and are generally safe for landfill disposal.