Standard replacement battery for MSA Optimair TL PAPR is a rechargeable 12 volt (nominal) nickel-metal hydride (NiMH) battery pack. MSA 10076108 standard fully charged battery with new cartridges should operate the MSA OptimAir TL PAPR for a minimum of four hours under normal conditions. Use only MSA standard battery charger for OptimAir TL PAPR for recharging the standard battery pack.