Battery voltage still low after BCM recall

[mont999]

Hello,

The battery readings on my 19 plate qashqai tekna are still low at around 11.6 volts with the engine off (using a reliable multimeter) , even after a few hours after a 100 mile run.
I tried a tip found on here about starting the engine with the bonnet open to bypass the charging system but no change for me. Are other owners experiencing low readings ?
It's enough to start the car (apart from once when I had to use a jump starter) ,but I've noticed as I have a dashcam running over a power magic pro system which turns the dashcam off in parking mode when the battery level drops below 12volts. The dashcam stayed on for several months from new ownership before starting to shut down after a few hours a couple of months ago. I thought this would improve after the recent BCM fault recall, after which I have noticed the stop start now kicks in a lot more but no change to the low battery reading.

[calnorth]

Q: Are other owners experiencing low readings ?
A: They probably won't know until....no start....

The general rule on batteries is that if they fall below approx 12.5v from full charge in a about 24 hours they are faulty. Or something is draining them..a so called parasitic discharge or leak.

I've had a dashcam assist in a battery discharge badly. Meaning the battery was not charged fully by my short journeys and the camera did not switch off automatically on ignition off. USB powering is risky because the USB ports are permanently powered with ignition off. Thats ok if you remember to unplug the camera at the right time. I power via the wiper power line which is ignition controlled.

There is a battery load test that can be performed by any auto electrician. Or you could disconnect the battery from the car, charge it fully and leave disconnected for 24 hours....monitor it for short time terminal volt drop.

The general charge rate for any battery is for 10 hrs. At least 13.5/14 volts should be attained in that time. So monitor it for 24 hours after that...disconnected from car and charger.

[MikeGC]

I thought this would improve after the recent BCM fault recall, after which I have noticed the stop start now kicks in a lot more but no change to the low battery reading.

I haven't had a recall notice and have no way of monitoring the battery voltage....
By the way what does the acronym BCM mean ?

[calnorth]

I thought this would improve after the recent BCM fault recall, after which I have noticed the stop start now kicks in a lot more but no change to the low battery reading.

I haven't had a recall notice and have no way of monitoring the battery voltage....
By the way what does the acronym BCM mean ?

Body Control Module which has controllers for the likes of battery/power and others. The update itself includes documentation which would detail each change to BCM (or other) software and likely not for customer consumption...unless you ask? Could be updated upon urgent ad hoc need or at periodic service.

Others...typical and manufacturer specific:

Types of ECU include Engine Control Module (ECM), Powertrain Control Module (PCM), Transmission Control Module (TCM), Brake Control Module (BCM or EBCM), Central Control Module (CCM), Central Timing Module (CTM), General Electronic Module (GEM), Body Control Module (BCM), Suspension Control Module (SCM), control unit, or control module. Taken together, these systems are sometimes referred to as the car's computer (Technically there is no single computer but multiple ones.) Sometimes one assembly incorporates several of the individual control modules (PCM is often both engine and transmission).[1]

https://en.wikipedia.org/wiki/Electronic_control_unit

[MikeGC]

Body Control Module which has controllers for the likes of battery/power and others.

Thanks, Cal

[mont999]

Cheers for the replies Cal I'll give that a go. The BCM recall notice I had mentioned it enabling power saving mode (I'll see if I can find the notice) which affected the charging system, which tied in with the stop start not kicking in even after long motorway runs.
The blackvue dashcam I have is hard wired in via the power magic pro so should stop any drain.

[calnorth]

Oh..I wasn't aware of power magic pro. Am now

My camera is controlled by ignition on/off and motion detect. So when the car is moving its recording to SD continually. Parked is motion monitoring and on motion detected is recorded to SD until motion ceased. That saves processing of course.

I've had my QQ Fiamm battery down to about 11.3v and still had good starting. Although its a worry at that level in winter because of increased cranking amps when cold. Below 12v we are on the battery edge and dependant on local temperature conditions.

I wasn't aware of any QQ power saving mode...which would make sense to me if it permanently disabled Stop/Start

[Weasel]

My battery has been pretty much OK since the BCM update, providing I use the car on a regular basis.

Though, yesterday morning the battery was reading 12.54v, but this may have been caused by the QQ not moving for the last 10 days.

[mont999]

How do you get the service menu view up ?

[calnorth]

How do you get the service menu view up ?