Pretec PCMCIA SRAM PC Cards feature high speed, reprogrammable, non-volatile solid state memory technology with low power consumption for maximum battery life and reliable data retention in a wide range of mobile and embedded applications. Each SRAM PCMCIA Card is designed with the dual back-up battery system; a replaceable but non-rechargeable 3V lithium battery (primary) and an on-board rechargeable but non-replaceable battery (secondary) allowing for replacement of the primary battery without data loss.