Battery meter says it´s 70%...need to replace it soon?

[jabicho]

Hi everybody, one of the first mods I did with vag-com to my 2009 A4 was enabling the battery meter.The thing is that up to now it´s always said it´s 100% charged...until last month.It started with 90% and now it´s even at 70%, I haven´t done anything to the car so I suppose there´s nothing there draining my battery.Yesterday I tried to recharge it but after 40 minutes the automatic charger I used said it was full ...although the battery meter on the car still says 70-80%, won´t go higher than that.In case of having to replace the battery,do you know if any coding is required? I mean, can I just change it, erase dtc with vag.com and that´s all? Any help is welcome...cheers

[rlarsen]

Is there enough water on the battery ??

Maybe you can see if the indicator on the battery is green or red - otherwise you need to take the screws off to check the water level - it should be ~ 1 cm. above the battery cells.

[Comp4k]

Hi everybody, one of the first mods I did with vag-com to my 2009 A4 was enabling the battery meter.The thing is that up to now it´s always said it´s 100% charged...until last month.It started with 90% and now it´s even at 70%, I haven´t done anything to the car so I suppose there´s nothing there draining my battery.Yesterday I tried to recharge it but after 40 minutes the automatic charger I used said it was full ...although the battery meter on the car still says 70-80%, won´t go higher than that.In case of having to replace the battery,do you know if any coding is required? I mean, can I just change it, erase dtc with vag.com and that´s all? Any help is welcome...cheers

I have no idea how that battery meter works, I had a dead battery and after I boosted it my battery bar was at 100%.....when really it should be really really low.

[jabicho]

The fact is that I´ve had a look at it and it´s difficult to tell, no "magic eye" and no "max-min" mark...this is what it looks like:


I´ve also found a way to check battery status and alternator via va-com, it´s on module 19 (CAN-getaway)...do you think this is the module for coding the new battery if we replace the original one? Other Audi models had a separate module for the battery, but this apparently this is not the case on A4B8

Measured value block 015:

Alternator, electrical status (OK / not OK)

Alternator, mechanical status (OK / not OK)

Alternator, thermal status (OK / not OK)

Vacant



Measured value block 016:

Alternator type (OK / not OK)

OK = Alternator type known

not OK = Unknown alternator type fitted

Alternator manufacturer

Alternator size

Alternator controller



Measured value block 017:

Battery identified (OK / not OK)

OK = Adapted battery known

not OK = Adaption value not known

Battery manufacturer (0-7)

Battery size (0-15)

Battery recognition (yes / no)

yes = Battery disconnected, no = Battery connected



Measured value block 018:

Battery voltage

Battery current

Current from or into battery (-400A to +100A); positive current = alternator charging battery, negative current = battery delivering current = no battery charging by alternator *2)

Temperature estimate, battery

Battery sensor temperature



*2) Active recuperation may also cause negative battery current. In this case there is no defect in the alternator.



Measured value block 019:

Battery charge in %

Battery charge in %

Corresponding to readout on MMI Car menu

Battery ageing in %

Derived from charged (0 % = very poor battery condition, 100% = very good battery condition)

Battery ageing in %

Derived from power output (0 % = very poor battery condition, 100% = very good battery condition)



Measured value block 020:

Current battery internal resistance in mW

Standardised battery internal resistance in mW

Battery internal resistance referred to theoretical internal resistance

Tappable charge in Ah

The higher the number, the better the battery condition

[jabicho]

Any more clues about what may be happening??