What is the battery life of the Lincoln Viking 3350?

This depends on which of Lincoln’s two Viking PAPR batteries is fitted, per Lincoln Electric’s official publication EE14.747:

• Standard battery (KP3937-1) — used in the K3930-4 system — runs about 9 hours at 180 lpm and takes about 3 hours to charge on the KP3932-1 charger.
• Extended battery (KP3938-1) — used in the K3930-6 system — runs about 16 hours at 180 lpm and takes about 4.5 hours to charge.

Both are Li-ion packs rated for roughly 500 charge cycles. The Viking PAPR is NIOSH 42 CFR 84 approved as a loose-fitting PAPR, APF 25, with a three-stage filter (spark screen → prefilter → HEPA). Only the genuine Lincoln battery and charger listed on your system’s approval configuration are covered by that approval — this is a manufacturer-listed fit per our four-tier system, so check your unit’s approval label before assuming a third-party or rebuilt pack is equivalent.