Hi
ive had a few electrical related warnigs over the last few days, airbag fault, forward alert not available, handbrae fault all once the car has started for about 20 secs.

On Friday i noticed a whine coming from the engine bay which is speed related.

Having had electrcial warnings on my previous RRS just before the alternator died i checked the battery voltage this morning after car had been stood overnight and had the following reslts :

Battery voltage 11.42v ( with IGN on no load lights etc off )

Battery voltage of 10.97v ( with engine running again no load lights etc off ) this voltage rose to 12v after about 1min of running.

So do you think its battery or Alternator "the whine makes me suspicous" or indeed both ???

cheers

Alternator!

Voltage should be much higher with engine running if alternator is doing its job. Care or it will take your battery with it. At 11.4 volts battery is marginal already. What does it read with ignition off and car asleep?

I was getting similar symptoms just before my alternator went Robin
2008 Range Rover Sport TDV8
Gone:
Jaguar S-Type V8 4.2 Sport
MGZTT 190 2.5

Is it easy to isolate the Alternator to test for a short time, i.e. with it isolated, does it whine? I know these Li-On batteries can give very odd symptoms. If my wife has had the heated seats and screen on during cold spells (Ford Mondeo), I can be 99% certain i'll get issues with the clocks working randomly, the radio doing its own thing and the auto wipers randomly working. A good charge and a reset fixes all this. 2019 5.0 SC SVA (Current)
2012 5.0 SC AB. Sadly written off by a campervan
23 plate Focus ST (Current)
1942 VEP Ford GPW Jeep (Willys) (Current)
1943 Whites M16 Halftrack (Current)
16 plate Eurofighter Typhoon, 2 x Eurojet engines with 20,000lbs thrust each. 1380mph

it measures 11.47 with no ign on.

When I did the last alternator on my previous RRS I put a new battery on at the same time. as bettery light came on and things like radio and heated seats would not work.

I also think Alternator is on its way out.

When mine was on its way out I called out Green Flag as the car wouldn't start.They jump started it and then tested the alternator in situe so its not a difficult task to get it checked. Just keep your battery well charged - CTEK or similar.

First signs of a low battery for me was, after starting, the display briefly showed Auto Handbrake Release not functioning but that message went away after about 10 seconds. However, when the alternator finally gave up the ghost, a run or just 109 miles totally knackered the battery. Robin
2008 Range Rover Sport TDV8
Gone:
Jaguar S-Type V8 4.2 Sport
MGZTT 190 2.5

The alternator looks like the culprit, you should be looking at around 14.5volt with the engine running.
The battery will be barely charging with a PD less than 1 Volt, hence your battery will be low. MY12 RRS HSE
Gone 4.2 supercharged RRS
Gone 90
Gone s2000