MPD's BK-57 is a surface-mounting AA battery contact. Normally used in pairs, these clips have a great price/performance combination for adding a AA battery to a PCB. The pair of contacts use pressure to connect with one AA battery, and multiples of contacts can make a series or parallel circuit through the PCB for groups of batteries. These contacts make it very easy to insert and remove a AA battery because of the excellent access afforded.

Phosphor bronze is the base metal, which is stronger than brass, with better spring properties. Phos-bronze is well-known for its durability, strength, low coefficient friction, fair electrical conductivity, and low thermal conductivity and is commonly used as non-ferrous spring alloy. Each SMD lead has a solder hole that contributes to the solder wicking up onto the AA battery contact for additional joint strength.