How long does the battery reserve last? (Audi A4 B5)

We calculate how long an electrical consumer can operate from the battery using the formula: service life = battery capacity x on-board network voltage divided by the power of the electrical consumer. But in practice, you should never count on the full capacity of the battery, but only on a charge up to 2/3 of its nominal capacity. In this case, you need to count, for example, on the following service life:

Battery	Parking lights	Parking lights	Emergency alarm system
36 A hour	about 28 hours	about 6 o'clock	about 3 hours
44 A hour	about 35 hours	around 8 o'clock	about 4 hours
70 A hour	about 56 hours	around 12 o'clock	around 7 o'clock

Effect of temperature on battery

The battery has a property to react to cold the worse, the lower its charge. In a completely discharged state, it is so sensitive that in frost it can freeze and burst. But when fully charged, the battery tolerates cold relatively well. Before the onset of cold weather, it is recommended to check the charge state of the old battery.