X Series E70 X5 3.0Si (N52K) OFFRD
When vehicle batteries are charged, the two gases oxygen and hydrogen are released by electrolysis.
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In a conventional wet lead calcium battery, the two gases hydrogen and oxygen are dissipated into the
atmosphere.
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In an AGM battery, the two gases are converted back into water: The oxygen which is created at the positive
electrode during charging passes through the permeable glass fibre fleece to the negative electrode. At the
negative electrode the oxygen reacts with the arriving hydrogen ions in the electrolyte to form water (oxygen cycle).
In this way, the gas and thus also the electrolyte are not lost.
Only in the event of an excessively heavy buildup of gas, i.e. excessively high pressure buildup (20 to 200 mbar),
does the pressure relief valve discharge the gas. In this process, the pressure relief valve does not allow any oxygen in
the air to enter. Because a valve regulates the pressure in the battery, the AGM battery is also known as a VRLA
battery (Valve Regulated Lead Acid).
Notes and instructions for service personnel
It is necessary when handling an AGM battery to observe some particular points pertaining to battery changing and
installation location.
Charging
Warning! Do not charge the AGM battery with
≥
≥
≥
≥
15.2 V. No quick-charging routines!
When charging removed batteries (so-called stand-alone batteries), do not exceed the maximum charging
voltage of 15.2 V at room temperature. Also when charging via the jump start terminal, do not exceed the
maximum charging voltage of 15.2 V at room temperature.
The AGM battery will be damaged even when it is only briefly charged with a charging voltage of more than
15.2 V. A charging voltage of more than 15.2 V is usually used in quick-charging routines.
Installation location
Warning! Do not install the AGM battery in the engine compartment.
The AGM battery must not be installed in the engine compartment on account of the high spatial temperature
differences, otherwise its service life will be significantly shortened.
Housing
Warning! Do not open the AGM battery.
The AGM battery must not be opened under any circumstances as the introduction of oxygen from the air will
cause the battery to lose its chemical equilibrium and be rendered non-operational.
Battery changing
Any conventional lead calcium battery can always be replaced by an AGM battery.
Using an AGM battery does not require any alterations to be made to the vehicle electrical system.
Note: The AGM battery is recommended for "problem customers".
"Problem customers" encounter a high energy throughput through their batteries. This high energy throughput
is caused by stationary loads/consumers (TV, independent heating, etc.) and a bad use profile for the battery
("chauffeur operation", short-distance driving, "stop-and-go"). The use of an AGM battery is recommended for
these problem customers.
RA AGM battery
BMW AG - TIS
07.02.2013 02:18
Issue status (12/2007) Valid only until next DVD is issued
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