CU2 - New Battery dead flat after sitting for 11 Days ??? What !!

[Cooldollar]

Hi All.
I have a near new (5 months old) Supercharge battery in my Euro. The cars charging system is working fine. I have just come home from 11 days away to find the battery absolutely DEAD FLAT. 0.2 Volts on my multimeter. Nothing was left on and the car was locked with the key fob.
I unlocked the car manually with the drivers door lock to get inside.
This is most unusual. Any ideas where to look for a fault would be greatly appreciated. The battery / car / charging system appeared to be working fine before I left. Will this complete discharge damage my battery ? I can't tell yet as it is on the trickle charger now.
Also when I connected the battery charger the indicators started to flash and horn give a feeble toot! What is all that about ?
Looks like a bit of pain resetting radio and memories is coming my way but fr the moment all I want to drive is my beautiful car.
Cheers and thanks for any advice in advance.

[Kuchiki81]

Maybe it's revenge for neglecting such a beautiful car

[DreadAngel]

When you say your electricals are fine, did you check the alternator etc?

Do you know how much power your car alarm uses? Cause if its a fancy one with all sorts of tracking, detering flashing lights etc then it could potentially use up quite a bit.

If possible, check the battery for dead cells etc too just in case it was a faulty battery from factory.

[antony]

I'm on my original battery,which is over 5 and a half years.

[bennjamin]

Crap battery ? Badly setup after market alarm ? Previous installed electrical accessory shorting somewhere ?
Yes your alarm will drain the battery over time , more so with little or no use.

A quick Google search shows people have done the math for a standard battery on a standard car with standard accessories , the alarm can fully drain the battery in 15-20 days. This is perfect conditions - excessive heat or cold or moisture will reduce this time , as too age of battery / internal condition and quality of battery.

Next time disconnect the negative terminal

[Martin77]

Hi there,
If the alternator is alright, there could be 2 possible faults.
1. The battery - once fully charged this can be taken to NRMA service centre where they can test the battery free of charge. It will tell the CCA rating of the battery and if it is under approx 80% it would fail it. You can get a print out of the test and submit the battery for warranty.
2. High drainage from a light or faulty equipment - if you have a multimeter, you can test the drain by disconnecting the positive terminal on the battery and connect the multimeter between the disconnected terminal and positive terminal of the battery. Probably good to use 10 A setting on your multimeter and remember to change the multimeter cable for current measurement. They say if it is above 50mA (0.05A), it could be a problem. If not auto electrician can do it easily.