LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> BMW >> 2012 >> 535xi GT >> Repair and Diagnosis >> Engine Performance >> Ignition System >> Engine Performance - Functional Description -- F07 >> Engine Performance - Functional Description >> Automatic Engine Start-Stop Function >> AGM battery
April 5, 2026: LEMON Manuals is launched! Read the announcement.

AGM battery

The automatic engine start-stop is used with the intelligent generator control (IGR). The much more frequent charging and discharging means that the load on the battery is very high.

The cycle resistance of AGM batteries means that they achieve similar results to conventional batteries with regard to service life despite the high load.

An AGM battery is a lead-acid battery. As compared to the conventional battery, the AGM battery has a glass-fibre fleece as a separator in which the electrolyte is fully absorbed. The AGM battery has a gas tight housing with pressure relief valve.

Fig 1: AGM Battery
G09872187Courtesy of BMW OF NORTH AMERICA, INC.