battery draining over 3 to4 days

[Johnnyboy65]

My Rover75 CDTI is fitted with new heavy duty battery and the alternator was replaced iast year. The battery is however going flat over a 3 to 4 day period which suggests that an electrical component is not switching off.


I would be grateful to hear if any other members have had this problem and if so, suggestions as to the identity of the cause.


Thank You.

[SD1too]

Originally Posted by Johnnyboy65

The battery is however going flat over a 3 to 4 day period which suggests that an electrical component is not switching off.

It could be that yes, but there's another possibility.

What is your driving pattern at the moment John? Are you doing mainly very short journeys, perhaps not switching off the heated rear window when it's not needed? Even the heaviest duty battery will eventually go flat if it doesn't have enough time to recharge, however good the alternator is.

Simon

[macafee2]

Tracing a drain can be difficult but start at the very beginning and prove the battery is ok. Fully charge the battery then disconnect the charger and leave the battery disconnected from the car.
Then test the voltage with a multi meter and then test again after 4 days.

Another test is to fully charge the battery and have someone try to start the car while you test the battery voltage and see what it drops to.

These may not be definitive tests but they are a good indication.

Another test, test the battery voltage of the battery, start the car and test again the battery voltage, it should go up, you may need someone to rev the car while testing.

Are any interior lights being left on such as the one in the boot?

I'm sure others will list "known" problems.

macafee2

[bl52krz]

As Simon said, leaving the rear window switched on, will take quite a lot of energy from the battery. If you look at the switch for putting the rear window on, you will notice that the warning light on it comes on when the temperature gets down to around 10 degrees automatically. Switch it off.

[Briodyjl01]

Does the car have highline? As if so disconnect the disk drive

[Johnnyboy65]

Many thanks to all who replied to my post with such pragmatic and useful advice, which I will put into practice. Great to have this support from the club.

[Johnnyboy65]

Many thanks for all good advice given. It is very helpful and much appreciated.

[xsport]

..... And dont forget the basic things such as battery terminals . Clean the insides of the clamps to posts and make sure they are not loose. Battery to earth connection could also give rise to problems. This can be done 10 mins remove and clean the earth connection and then refit. Nothing to lose here !!