Battery Eater

FrattonEnder · 2nd November 2020, 13:46

My 2005 ZT diesel has got herself an appetite for munching through the battery if she's not run a few times a week. A couple of time this year she's done it after being sat for about 10 days. As far as I'm aware, I've no lights left on, nothing plugged into the 12v socket so I'm at a bit of a loss what's causing it.
Read somewhere that blocked plenums causing water backing up into the ECU can cause a sudden battery drain - they've been cleared out only 4 or 5 weeks ago. Battery was brand new back in May and was taken out and fully recharged in September and taken for a run 2-3 times a week up until mid October.

I know the simple solution is to run the old girl every day, but it's not always practical, especially as it's a bit of a rolling resto and now with 3 cars on the drive, she's been relegated to the back of the queue.
Any ideas?

suzublu · 2nd November 2020, 14:21

Have you got factory fitted sat nav?

FrattonEnder · 2nd November 2020, 14:40

Quote:

Originally Posted by suzublu

Have you got factory fitted sat nav?

Nope, poverty spec on that front!

roverbarmy · 2nd November 2020, 14:59

Are you sure that the battery is OK. One cell down may still give a decent voltage reading but will fail under load. (ie 5 cells at 2.4 volts = 12volts but the sixth cell may be jiggered).

FrattonEnder · 2nd November 2020, 15:55

Quote:

Originally Posted by roverbarmy

Are you sure that the battery is OK. One cell down may still give a decent voltage reading but will fail under load. (ie 5 cells at 2.4 volts = 12volts but the sixth cell may be jiggered).

I hope it's OK. It was brand new back in May. And not a dodgy brand either - went for Bosch. If it's not, I won't be happy.

macafee2 · 2nd November 2020, 16:01

fully charge the battery off the car, leave it off the car for 10 days, refit and see what happens. It would be better if you have a test meter, charge the battery and see what voltage you get across the terminals, once you take it off charge and 10 days later.
I say 10 days as op said 10 days

Have you an ampmeter? You could then test what amperage is being drawn with everything turned off. screwfix do one that is not too expensive

even new batterys can be faulty, had one a coupe of years ago from Halfords but they changed it no problem

macafee2

2nd November 2020, 13:46	#1
FrattonEnder Avid contributor MG ZT Join Date: May 2020 Location: Gloucester Posts: 233 Thanks: 40 Thanked 47 Times in 28 Posts	Battery Eater My 2005 ZT diesel has got herself an appetite for munching through the battery if she's not run a few times a week. A couple of time this year she's done it after being sat for about 10 days. As far as I'm aware, I've no lights left on, nothing plugged into the 12v socket so I'm at a bit of a loss what's causing it. Read somewhere that blocked plenums causing water backing up into the ECU can cause a sudden battery drain - they've been cleared out only 4 or 5 weeks ago. Battery was brand new back in May and was taken out and fully recharged in September and taken for a run 2-3 times a week up until mid October. I know the simple solution is to run the old girl every day, but it's not always practical, especially as it's a bit of a rolling resto and now with 3 cars on the drive, she's been relegated to the back of the queue. Any ideas?

2nd November 2020, 14:59	#4
roverbarmy This is my second home Roverless + 1.7D Sportage Join Date: Aug 2014 Location: East Norfolk Posts: 7,050 Thanks: 729 Thanked 2,021 Times in 1,449 Posts	Are you sure that the battery is OK. One cell down may still give a decent voltage reading but will fail under load. (ie 5 cells at 2.4 volts = 12volts but the sixth cell may be jiggered). __________________ Oil in my veins!

2nd November 2020, 14:21	#2
suzublu This is my second home rover 75 1.8 vvc club se wedgwood blue Join Date: Aug 2009 Location: Seaton Carew Posts: 26,922 Thanks: 65 Thanked 7,142 Times in 4,642 Posts	Have you got factory fitted sat nav?

2nd November 2020, 16:01	#6
macafee2 This is my second home Rover 75 Saloon & Tourer Join Date: Sep 2012 Location: Lincoln Posts: 14,931 Thanks: 1,630 Thanked 3,032 Times in 2,181 Posts	fully charge the battery off the car, leave it off the car for 10 days, refit and see what happens. It would be better if you have a test meter, charge the battery and see what voltage you get across the terminals, once you take it off charge and 10 days later. I say 10 days as op said 10 days Have you an ampmeter? You could then test what amperage is being drawn with everything turned off. screwfix do one that is not too expensive even new batterys can be faulty, had one a coupe of years ago from Halfords but they changed it no problem macafee2