How long does an Airmax battery last?

It depends which Jackson Safety Airmax system and market you have — the figures our records hold differ by SKU set and source:

• Airmax Elite (model R60 in the EU, 40839 kit in the US): the Jackson Safety EU product page states 8 hours on a new filter with a Li-ion battery, recharging in under 4 hours over 300+ charge cycles. A US technical data sheet states the same 8-hour/14.4V Li-ion spec, while a third-party mirror of the EU R60 manual instead states a 14.4V/2.6Ah battery good for 500 charging cycles — a possible spec update, not reconciled into one number here.
• Airmax+ (the separate, higher-output blower line): the manufacturer states up to 10 hours with a new P R SL filter at 170 l/min, using a 4-cell 7.4V/5200mAh Li-ion battery with a 5-hour recharge.

Runtime depends on a new filter and airflow speed setting — a clogged filter or higher speed will reduce it. Always use the battery/charger listed for your specific Airmax model and check your unit’s manual.