Flat battery


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Jul 27, 2009
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not used my car for 2 cars went to start today and battery was flat flat no lights on dash nothink .

been on charge since 8.30 and is now up to 80% at 12.00

any help what might cause it to get this flat

only got battery in October .

Seems something is pulling the battery down. First thing is to check the battery health...
If you can establish that the battery is good, you really need to get a parasitic drain test done to identify what circuit is pulling the battery down. Common stuff: interior/exterior lights, alarm sounder, contact switches...
battery is good and charging.

have noticed that that hazard light stays on and the light under the main light switches so have googled it and people are saying that that is the problem ?

have just disconnected it and see what happens
I had this with my bmw with a 2 month old varta battery on it turned out it was a faulty battery.
Then i put the top exide battery on and that went faulty after 6 months.
Never had a faulty battery in over 40 years of driving and have always bought the top varta batteries.
Back with varta and 12 months in so far no problems car started first touch of the key after standing just over 2 weeks.
my hazard warning triangle stops on all the time so from what I can see I have some sort of fault ?
Is the carpet dry on the front passenger side.
Any other things playing up at all locking/windows anything.
will check later every think ok apart from rear passenger side light keep getting a rear parking light fault will remove cluster today
no I have one on order will post on here when it turns up . batterys ok and charges ok
found these fault codes

IMG 3626 IMG 3627 IMG 3628 IMG 3629
The flat battery has nothing to do with those errors.
I don't know what is with that flap error but the others are connected. The heater is broken. This is common. Mine is also.
Most of the times it can be repaired. Some electronic parts need re-soldering.
Is not clear though how long did the car stayed unused.
had car mopped on wednesday then not went out until Monday and battery was flat ;( possible the chap that mopped it left things on and battery was poor but not sure also I have a on board camera which was left on so might of been that

the hazard warning switch I have noticed is constantly on and has 3 leds in it as to was the coming home light switch .
strange mine stops on constant wonder how much current it draws
It can't drain the battery that fast. Its a LED... it doesn't consume that much.
Did you check after a few minutes after you locked the car if it is still on? Without unlocking...
This needs a parasitic drain test. Coz you don't have a multimeter you can't do much of diagnostic valve, save unplugging suspicious consumers and seeing what happens...without monitoring current after lock-down this it a sketchy process, however.
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multimeter on order will need some help once it turns up.

doesn't go flat over night
got multi meter .

not been in car since Friday night and needed a quick charge today before it would start.

any help on what I need to test please would be a great help ?
rite so swapped battery to check and have found that the duff battery which was new in October after being fully charged went down to 12.1 volts after 6 minutes of not being on the car . the battey which I put back on the car has been stood for 6 months had a quick boost charge 10 days ago and was still on 12.4 volts so think battery faulty but tested ok bit strange

after 4 hours its down to 12.0 volts
The hazard switch staying on suggests something is keeping a can network awake.. The switch won't be the drain, whatever keeps it awake will be the drain.
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what sort of thing will keep the can network awake ?
ALSO if my control module for auxiliary air heater is faulty who and test this and repair if needed please ?

Set meter to ammeter function:

  • Disconnect battery negative (you may lose clock, temp memory and trigger under voltage faults across ECUs - driving vehicle should cure any MILs activated due to battery disconnect)
  • Connect ammeter in series between negative terminal and battery negative post (ensure leads are in correct position for checking amps)
  • Lock vehicle (you will also need to close bonnet micro switch integrated in latch/lock mechanism)
  • Leave for 20-30 mins to allow network to sleep
  • Check reading on ammeter (if less than 50mA you do NOT have an unacceptable drain. If greater please post value here)


PS - are you able to load test your battery?
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ok will do that today . put spare battery on yesterday which had been stood for a week after charging and reading 12.4 drove about yesterday no probs today reading 12.1 and car wont start .

how do I check (if less than 50mA what setting on meter

also how do I remove climate control unit
which setIMG 3681 ting do I set meter to please
which setting do I set meter to please

Spin the dial clockwise to amps (A) "200m" on the green section on the right at about 4 o'clock.

PS - I'd lock your car before disconnecting battery and attaching meter in case this draws more than your meter can handle. Furthermore, if you are unsure about working with the meter and carrying out basic tests, I'd suggest reading the manual. I'm happy to help with testing but don't want you to blow your meter making a mistake...its easy done...as I'm sure everyone who's worked with a meter ever can agree with.
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ok test on the way set to 200m at the moment its on 08.5 after 10 mins
looks like im drawing 8.5 amp s

took interior light fuse out and went down to 5.8 I have leds installed
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stop doing tests as had to go out .

if at 200m and said draw was 8.5 is that 8.5 amps
poss thinking alternator resistor fault ?
So 8.5 at 200m scale is 8.5mA, which is tiny - on 200 mA 199.999 mA is the full scale.
Set your meter to 10A which will confirm your reading in Amps. Should read 0.0085 - or just 0 depending on accuracy on that scale.
To confirm, if your getting 8.5mA draw when vehicle is locked you don't have an obvious problem parasitic drain. This doesn't mean something isn't coming on intermittently and pulling things down. To check this you need a decent scope.
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Ok so it's 08.5 amps if set to 200m

What could drain that much ?

Have disconected b+

Could climate control faulty cause it ?
quick update with alternator wire of this morning with old battery on car is reading 12.36v car was unlocked

does car need to be locked to go in to sleep mode ?

have noticed when locking car that after a few mins the current draw drops to say 8.5ma does that mean car is going to sleep ?


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