Flat battery

[discotwinturbo]

Just got back from 6 weeks abroad. Touareg started nicely. Disco flat.....not even a glimmer of light. Battery down to 7.6 volts.

Been on charge all day, with only a 5 amp charger (did not want to hit it with the big one), and back to 12.1....will leave it a little longer before I fire her up.

Next time, I will disconnect the battery. A good comparison between the D4's systems and a 4 year old car. Seems as though the D4 does not go into a full sleep. Touareg actually shuts systems down as the battery level drops. Was really looking forward to driving her....will have to wait a little longer.

Brett....

[driftn69]

G'day discotwinturbo,

I seem to remember reading or it being suggested (by the stealer I think) to me that if a D4 is to be left unused for an extended period to lock the suspension so that it doesn't keep levelling itself thus draining the battery.

Cheers Colin

[discotwinturbo]

Interesting....thanks for the tip Colin.

Have just fired her up.....she thinks its 1st Jan 2009.

Locked her up for the night and locked the suspension just in case. Will take her for a good spin tomorrow.

Brett....

[Graeme]

What do you mean to lock the suspension? Is that referring to locking in crawl mode? If so, I can't see any difference to just access height, being the same low height.

[camel_landy]

I would assume the locking in 'Access Mode'.

You might want to just get it checked out as the systems should lock down to prevent excessive battery drain. However, if there is a faulty switch or something, this will prevent the car from shutting down properly and therefore flatten the battery.

M

[stewmair]

Went away for 11 weeks with the aux battery disconnected and a maintenance charger on the main battery. No problem on return.:D

[drivesafe]

Hi Brett and there can be a whole host of reasons why a battery goes flat over that length of time but with a battery voltage of 7.6v, I would suggest there is more to it than just normal vehicle discharging.

Most devices stop drawing power once the battery voltage gets to 10v and a battery is flat at 10.5v, so you will need something like a light glob left on to continue to draw the battery down that low.

One other point, how well charged was your battery before you left the D4 for so long?

If you had been doing noting more than short trips before you left the D4 parked up, the battery may have been in a low state in the first place.

[discotwinturbo]

Hi Brett and there can be a whole host of reasons why a battery goes flat over that length of time but with a battery voltage of 7.6v, I would suggest there is more to it than just normal vehicle discharging.

Most devices stop drawing power once the battery voltage gets to 10v and a battery is flat at 10.5v, so you will need something like a light glob left on to continue to draw the battery down that low.

One other point, how well charged was your battery before you left the D4 for so long?

If you had been doing noting more than short trips before you left the D4 parked up, the battery may have been in a low state in the first place.

G'day Drivesafe,

The two days before we left we were carting horses about 100kms each way south of home, then also another trip at about 75kms from each way.

The VW was used little that week and battery is just over 4 years old. VW still had door alarm light pulsating before I unlocked it.

Seems as though there must be something drawing current. My reversing camera monitor is wired to permanent power. It was off, but has a little red led light when off....but doubt that would chew enough power. Led light on camera was off when the battery was flat. All interior lights were switched permanently off. Auto lights off.

Have been camping a fair bit, and left her off for up to 5 days, and starts ok.

I think next time I will disconnect it.

Brett....

[Ferret]

... suggested (by the stealer I think) to me that if a D4 is to be left unused for an extended period to lock the suspension so that it doesn't keep levelling itself thus draining the battery.

I have a recollection of being told, or perhaps reading, this too.

[Graeme]

The two days before we left we were carting horses about 100kms each way south of home, then also another trip at about 75kms from each way.
My 2009 D4 had a flat battery the morning that I then drove nearly 600 kms to have the vehicle serviced. The report was that the battery was OK but not fully charged so it was put on a charger for a while. I think the battery must be on its way out because if its not charged after a 600 km run, its never going to be. It was the last service before the end of warranty too, so no 2nd chances of getting a new battery unless it fails with then next 6 weeks and I have time to get to a dealer.

[kiwi48]

I have had two flat battery problems with my D4 after being away for 5-6 week periods.

The first was a year ago. Couldn't even open doors. Called road side service, Mondial, who replaced the battery without charge. But a few months back starting became a little sluggish and at service LR, Austral, replaced the battery under warranty - the previous replacement battery CCA was undersized.

Returned from 6 weeks o/s last week. "New" battery was dead flat, again couldn't open doors. Called Mondial who responded via Allianz who I presume they have contracted out battery issues. After some trials and tribulations, including calling in a second service vehicle which had equipment with sufficient capacity to start the D4, I was underway again. Allianz reckoned the battery was at 2v.

Took the vehicle straight to Austral who checked the battery and said it was OK for charging. When I got home again I put the battery on a recondition charge with my Citek 7000 and to date it seems to be performing OK.

I have a Traxide dual battery system in the vehicle. It is set up so that the battery is in the cargo compartment and when not required is removed and the cable and Anderson plug are rolled up and stored in the jack stowage area. This was the case when I was away.

Austral considered that the dual battery system was the likely cause of the problem (although when I asked them about this in the first instance a year ago they said it shouldn't be a problem) and said that whilst in day to day running wouldn't cause problems, if left idle for some weeks it could drain the main battery. They suggested that disconnecting the red connector on the cable leading to the rear of the vehicle would resolve the problem. On reflection this doesn't make sense if the auxiliary battery is removed and in any event I would have thought the the dual system would protect against discharging the main battery.

Drivesafe, can you comment on this? Are there any checks I can do to ensure the system is not at fault?

[rufusking]

Disconnecting the thin ground wire from the controller (I think it's brown on mine) will disable it so any current used to sense voltage will be turned off.
You could install a small switch or a couple of quick connectors to it.

[drivesafe]

Hi Kiwi and if you had a fully charged battery when you parked the D4 for the 5-6 week, the SC80 would have taken 3 to 4 week to discharge the cranking battery ( when only one battery is in the D4 ) down to 12.0v.

At this point, the SC80 turns off and then draws about 15ma and would take at least another 50 days to discharge the battery down to just above 11.6V and you could still start the D4 with this battery voltage.

Now the problem with the figures above is that it does not cover the power used by your D4 for it’s own housekeeping.

So could the SC80 be responsible for flattening your battery, yes but there is, as you can see, a little more to it than a simple answer ( or excuse ).

I would suggest to anyone, whether they have a dual battery system or not, to take the negative terminals off all batteries in the vehicle if it is going to be left for that length of time.

Hope this is of some help to you Kiwi.

[kiwi48]

Thanks guys. After my first experience I had intended to disconnect prior to going away again. However as often happens in the last minute rush somethings get missed. Not again, I hope.

[drivesafe]

Disconnecting the thin ground wire from the controller (I think it's brown on mine) will disable it so any current used to sense voltage will be turned off.
You could install a small switch or a couple of quick connectors to it.

Yep, good one rufusking, by putting a switch in the brown earth wire or Green/Yellow earth wire ( depending on which isolator you have ).

When you turn the switch off, you will completely shut down my isolator and disconnect the batteries at the same time.

JUST DON'T FORGET TO TURN THE SWITCH BACK ON AGAIN, WHEN YOU WANT THE ISOLATOR TO OPERATE!

[Disco4pilot]

Hi Kiwi and if you had a fully charged battery when you parked the D4 for the 5-6 week, the SC80 would have taken 3 to 4 week to discharge the cranking battery ( when only one battery is in the D4 ) down to 12.0v.

At this point, the SC80 turns off and then draws about 15ma and would take at least another 50 days to discharge the battery down to just above 11.6V and you could still start the D4 with this battery voltage.


Tim does the USI160 work the same way?

Can you put a switch in this to turn the 160 off in the same way as the 80?

Cheers

[drivesafe]

Hi Disco4pilot and with the user selectable switch in the In-Cab module, if you set the switch towards the LED, the USI-160 will shutdown ( turn both relays off ) when the common voltage of the batteries drops below 12.6v, and the USI-160 will then only be drawing about 15ma.

Your batteries self discharge at a higher rate than 15ma.

So if you are planning on leaving your D4 parked up for long periods of time, simply set the switch towards the LED.

If when you come back to your D4 and find the cranking battery has gone flat, flick the switch away from the LED and then back again and you will now be in Emergency Jump Start mode and you should be able to start your motor off the auxiliary battery.

If you are planning on leaving any vehicle parked up for a month or more, I still recommend you take the neg lead of all batteries in the vehicle, no matter what vehicle it is or whether it has or has not got a DBS fitted.

[rufusking]

With the neg lead removed I assume you will need to use the key in the passenger door to lock and unlock. What happens to the alarm system when it runs down?

[drivesafe]

Hi rufusking and correct me here if I’m wrong but there is no backup battery in the D3 or D4 alarm, so it’s not a problem.

If you have an after market alarm fitted then you need to have a way around it.

[rufusking]

I thought I read somewhere that there was, I'm happy to stand corrected.

[scarry]

I thought I read somewhere that there was, I'm happy to stand corrected.

Maybe thinking of D2,it definitely has one.

[Crampeye]

G'day Drivesafe,

The two days before we left we were carting horses about 100kms each way south of home, then also another trip at about 75kms from each way.

The VW was used little that week and battery is just over 4 years old. VW still had door alarm light pulsating before I unlocked it.

Seems as though there must be something drawing current. My reversing camera monitor is wired to permanent power. It was off, but has a little red led light when off....but doubt that would chew enough power. Led light on camera was off when the battery was flat. All interior lights were switched permanently off. Auto lights off.

Have been camping a fair bit, and left her off for up to 5 days, and starts ok.

I think next time I will disconnect it.

Brett....
Not sure if this means much, but in a lot of the new vehicles, when you put the interior lights to off, the system keeps pulsing power through the circuit and discharges.

The Commodores and Falcons we use at work will run flat in this mode within 12 to 16 hours and we run higher output alternators to keep all the electrics pumping while working.

Might be food for thought if the battery came back ok.

Cheers