AO Silver Member
Join Date: Nov 2007
As some of you may remember, my battery and BCM were replaced due to HRW and SS not working less than 2 months ago. HRW has been working so far as did SS cutting in quickly. However the SS did not work/cut in the whole 30 min journey today. Battery is new so it's not that. The voltage indicated in the 12v plug extension I have under armrest has been showing ~14.4 V last 2 days, normally it sits ~13.2 V when presumably the State of Charge is sufficient. There appears to be a complex logic to the whole charging algorithm which also controls functionality of HRW, SS etc. It seems to charge at 14.4v when battery SOC as calculated by/reported by the IBS is below a threshold (80%??) and if above the set threshold it drops the charging voltage to 13.2V but raises to 14.4V in quick increments to 14.4V under braking which drops back to 13.2 soon as foot is off brake pedal. This behaviour is not observed during engine braking, only foot braking in all DNA modes, irrespective of whether SS is enabled or disabled (my usual setting).
I wonder if SS is disabled when charging at 14.4V meaning the SOC is not high enough for engine to stop and start? However absurd that logic sounds as the car still appears to have enough charge to stop and starting by driver! I will continue to observe and see if SS works when charging at 13.2V.
I read on VARTA site that fitting AGM battery to non AGM would cause issues with BCM logic due to different charging characteristics. So not sure how they replaced with AGM under warranty??
Giulia 2.0 T4 MA (2017), Triumph Speed Triple 'R' (2016).
159 2.2 JTS - 2008 - Goodbye Feb 2017.
Ducati 899 Panigale - 2014 - 2016.
Kawasaki Ninja ZX 6R - 2004 - 2014.