Ongoing Battery problem

[Ginny]

Hi everyone, I was wondering if you could help solve my ongoing flat battery occurrence. The car is a 1998 Subaru Forrester petrol permanent 4WD Automatic 1990cc. For past three years after installing a new battery if left in the garage for 1-4 weeks the battery discharges and clicks but fails to turn over.  There is no evidence of lights being left on or doors left open. The battery has been tested two independent credible auto electricians who both agree the battery is not at fault and cannot identify the reason for the battery discharging.  Please see attached the battery, charging system starter and drain test results from the auto electricians. https://1drv.ms/a/s!AiB8yIzUeXO3jRRkL1gF137J-Kcp

The battery is now 7 months old.  The vehicle has not been modified and no additional electrical equipment has been attached except for a CD stacking system.  There is 100,000 kms on the clock.

Many thanks in advance for your thoughts.

Ginny

 

[Andy™]

start with turning everything off and checking that load is being drained from the batery

 

[ProDave]

I have a Forrester and even when we went to Australia for a month and came back it still started fine, so normal consumption, e.g built in alarm, should not flatten the battery that quick.

Your report won't show kn my browser. The important figure is what current is being drawn from the battery with the key out, everything off and the door locked?

My first suspicion would be the CD changer incorrectly wired to a permanent feed.

 

[Sharpend]

Have your alternator checked, a faulty alternator can drain a battery whilst the vehicle is not in use. 

 

[apprentice87]

It most certainly can...

Mine on my jeep then decided that it wanted to be extra powerful.. I was sitting in it with the engine running when suddenly the voltmeter on the dash went off the scale.. I switched it off and went and got a multi meter to measure the voltage. I started the engine went round the front, was just about to connect the meter when all smoke came out of the alternator... Only £400 for a new one..

john..

 

[ruston]

Reading between the lines  this is a low mileage vehicle . Has the problem been that the vehicle is stored and only used infrequenty ? 

If this vehicle has been parked up with an already depleted battery and other redundant systems are requiring power for long standing periods , this may evenntualy draw the battery reserve level  to a state that it will not produce the high cranking amps to start a 1900cc engine.

Even with the ECU asleep there will be a small draw on the battery , enough in time to take your reserve down to below it's required starting level.

 All of the above posts are also valid.

 I presume the auto electricians did as suggested in above posts?

 

[Geoff1946]

It is common for there to be a small continuous discharge into vehicle systems in "standby", eg central/remote locking, alarm, audio gear.  If its indoor and power is available  a float charger will solve it. If it's outdoor a small solar panel.

 

[Sidney]

There's a very good guide to tracking down battery drain here (Admin please remove if not allowed): http://www.disco4.com/forum/robbies-guide-battery-quiescent-drain-testing-119574.html?highlight=battery+drain+guide

I would also recommend you start using a battery maintainer when your car isn't in use, it will keep the battery topped up. I have used both CTEK and Optimate to geed effect.

 

[ruston]

As above If it is standing for long periods.