9V Battery

grabcad

The nine-volt battery, or 9V battery, is a common size of power source, initially developed for early transistor radios. It features a rectangular prism form with rounded edges and a polarized snap connector at the top. Common applications include walkie-talkies, clocks, and smoke detectors. Available in various chemistries such as primary carbon-zinc, alkaline, primary lithium iron disulfide, and rechargeable forms like nickel-cadmium, nickel-metal hydride, and lithium-ion, this battery type has phased out mercury-oxide versions due to mercury content. Identified as NEDA 1604 or IEC 6F22 (for zinc-carbon) and MN1604 6LR61 (for alkaline), it is universally marked PP3 - initially reserved for carbon-zinc but now used for all chemistries. Most 9V alkaline batteries comprise six individual 1.5 V LR61 cells, while carbon-zinc types consist of six flat cells in a moisture-resistant wrapper. Primary lithium versions use three cells in series.