Mysterious flat batteries

**drivesafe** · 8th June 2012, 07:31 PM

Hi folks and this is a weird one and I’m hoping someone out there may have come across something similar.

I have a D4 customer who has had a continual flat cranking battery for around 18 months and the other week the battery was replaced by the dealer, even though at times the dealer has had the D4 for a week at a time and not a problem.

Then the customer would drive his D4 home and with in a day or two, flat battery.

One of my dual battery kits was fitted, hoping to fix the problem because it was thought the problem might have been caused by Shopping Trolly Syndrome, where it is continually only driven for a few minutes at a time, except for the occasional long trip away.

A special version of the SC80-LR battery isolator was also fitted. This had a much higher cut-out voltage, but this didn’t change anything, and no matter what cut-out level was set, the auxiliary battery was always left with it’s voltage at or near the cut-out level.

So the isolators worked, the auxiliary battery never went flat and the owner got into the habit of measuring his cranking battery before he tried starting his D4.

Most of the time his battery was just to flat to start the D4 but on a number of occasions, where the battery was only down to 11.5v, he had no problem starting his D4.

A battery with an SoC of 11.5v will start most vehicles but the battery must be in good nick, so this indicates his battery is not the problem, and because the auxiliary battery is always at the cut-out level of the SC80-LR, this rules the isolator out as being the problem.

While away, there is never a problem, no matter how long he parked his D4 at what ever camping site he was at, and to make things even weirder, today he tells me he was so fed up with his battery going flat that he began backing the D4 into the garage to make it easier to get a jump start, but not once while the D4 was backed in, did the battery go flat.

Now over the last few years I have been hearing some strange problems being caused by these new Smart Power Meters, so when he told me about only having flat batteries when he parks front first in his garage I asked him if he had a Smart Meter in his house.

About 18 months ago, his old power meter was swapped over to a new Smart Meter and its located on the back wall of his garage.

To my question, has anybody else got one of these new Smart Meters fitted and have they suffered any mysterious flat batteries with no obvious cause?

**MR LR** · 8th June 2012, 08:12 PM

Sounds like witch craft LOL, where is the aux battery? if its in the back of the D4 does it go flat when reversed in?, if the meter is the problem can he try it with other cars and get the same result? and why doesn't he just back in all the time if this solves it? I always reverse anything in, bit of a habit. If its the 'smart' meter i would show it the blunt end of an axe and then see who's laughing, but its not my house so i don't need the power

**inside** · 8th June 2012, 08:23 PM

OK long shot but two things to confirm.

Is the owner locking his car with the remote at home? Some FL2 owners have been advised to do this after continual flat battery problems and it has solved the issue.
Are there any bluetooth devices in range that may be keeping the entertainment system awake overnight?

It has to be environment related because it's not happening at the dealers. Can you turn the smart meter off?

**Blknight.aus** · 8th June 2012, 08:25 PM

welecom to the KFFI problem

Key Fob Frequency Interferance.

same as the D2 wont start in front of a chemists. the signal used to do the remote reading of the meterbox is likely the same as the fob...

Not sure if its the same as some of the other euro cars that get imported but if you can flip it back to the euro frequency set and get the euro fobs (or jap ones) it might solve the problem.

**drivesafe** · 8th June 2012, 08:30 PM

Hi mr lr jnr, it’s not that the battery itself is flattened by the meter and in this case, with the auxiliary battery mounted in front of the cranking battery, the auxiliary battery is closest to the meter but is not effected.

What I have read about these smart meters is that they can cause problems with Bluetooth equipped gear and in this case, the Bluetooth in the D4 may be kept active, which in turn means the D4’s computer are not going to sleep, causing a continual drain on the cranking battery.

This is just my theory at this time and one case does not make it a confirmed cause.

**Blknight.aus** · 8th June 2012, 08:38 PM

try the havoc some people have on the base when the guys who do the tests on the tech that lets the plane find the things it wants the missiles to hit in the air...

many many people with many doors turning a key many times in seemingly random patterns....

I just glow it out (cursed vege oil likes a glow to start and the tdi IS pushing 400K Km) and kick it once.

yes, I can see how all this newfangled keyless tech is so much better and more reliable.

**slug_burner** · 8th June 2012, 08:38 PM

Strange one. Dave's fob freq theory is good for a starting issue but does not explain a flat battery.

Can we have it confirmed that the starting problem is due to a flat battery?

**Graeme** · 8th June 2012, 08:52 PM

Originally Posted by drivesafe

What I have read about these smart meters is that they can cause problems with Bluetooth equipped gear and in this case, the Bluetooth in the D4 may be kept active, which in turn means the D4’s computer are not going to sleep, causing a continual drain on the cranking battery.

Does the blue-tooth indicator on the console happen to stay on with the ignition off and his phone far away or off?

**drivesafe** · 8th June 2012, 08:53 PM

Hi Slug Burner and yes it is a continual flat battery that is the main concern.

The Fob Key problem is well known and the D1s were renowned for having a problem with frequency interference with a regular problem being caused if someone parked their D1 near the entrance to an Amcal chemist, because the anti shoplifting gear transmitted at the same frequency as the D1 fob key.

**drivesafe** · 8th June 2012, 08:54 PM

Originally Posted by Graeme

Does the blue-tooth indicator on the console happen to stay on with the ignition off and his phone far away or off?

Can’t answer that Graeme be I will ask him when he rings me again.

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