Power Extended Environmental Monitoring Sessions with High-Capacity TSI Power Maximize your air quality and particulate sampling without interruption. This Li202SX-7800 replacement battery is engineered for TSI's DustTrak II and AeroTrak series of portable aerosol monitors and particle counters. With a high 84.24Wh (7800mAh) capacity at 10.8V, it provides the long-lasting energy needed for all-day indoor air quality (IAQ) assessments, industrial hygiene surveys, and environmental monitoring in the field.