The AGM battery is recommended for "problem customers".

[omodos]

Hello to all, after my saga of using a ctek charger (with success!) to charge my 1 year old bosch silver plus I decided to scan the web for info on car driving style and how it affects battery (my alternator is fine I was told so was the battery, so this drain after 1 year could well have been caused by a parasitic drain and or not driving ‘correctly’ )
I found the following bmw tis and this related to all e53 and newer X5’s all interesting stuff but what caught my eye is below, just curious to see what other think too:

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




BMW Workshop Manuals > X Series E70 X5 3.0Si (N52K) OFFRD > 2 Repair Instructions > 61 General Electrical System > 20 Battery > 9 RA AGM Battery > Page 2324

When vehicle batteries are charged, the two gases oxygen and hydrogen are released by electrolysis.

In a conventional wet lead calcium battery, the two gases hydrogen and oxygen are dissipated into the
atmosphere.

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.

[powers1]

Nice share ,Omodos

[dkl]

This just look like a "band-aid" to just avoid diagnosing an excess parasitic drain on those "problematic cars" on BMW's part. With that said, I still went ahead with replacing the batteries on both of my cars with AGM this past summer - not as a band-aid, but as a "safety net". I don't have to throw on the charger as often if and when I leave the car sitting longer than usual.

[omodos]

yup have to agree with you DKL, anyhow I have still yet to trace the mystery wiring in the back of the X5 - I suspect it leads to the source of my power drain ie a clapped out gps tracker or its backup battery....in the meantime the ctek seemed to have worked wonders on the lead acid battery....