Flat battery

Mike24 · 14th March 2017, 19:11

About a month ago my wife moved the driver's seat (electric memory) ready to go shopping, got in the car, but it wouldn't start - flat battery. She hasn't driven the car since, so the driver's seat hasn't been moved. This afternoon I moved seat in order to vacuum the footwell (doesn't happen very often), got in the car this evening to visit friends - flat battery...

The battery was in the car when I bought it nearly three years ago, but, apart from these two occasions, has never given any trouble. I am wondering which is more likely; that the battery is coming to the end of its life; that, somehow, moving the driver's seat is causing a rapid drain on the battery; or neither of the above?

I've just though of another possibility; I've been having trouble lately with the windows not working properly - perhaps its something to do with them?

Any suggestions gratefully received.

Mickyboy · 15th March 2017, 07:57

Pop a multimeter across the battery terminals, and check the voltage a good battery will have around 12.6 volts, then with the engine running it should show around 14.2 volts.

That way you can eliminate the battery & alternator, obviously you need to get it started first, a set of jump leads or on a battery charge overnight with the battery off the car would be a decent starting point. I'm sure that the ECM won't allow starting below 11.9 volts

Mike24 · 15th March 2017, 09:19

I've charged the battery over night and put it back on, so the car starts fine at the moment. I am on holiday at the moment (just happened to have a battery charger in the boot!) and will try to buy a multimeter today to test voltages.

Mike24 · 21st March 2017, 11:26

Having bought a digital multimeter and waited for some fine weather, I've just been out to test the battery voltage; initially it was reading 12.45V with the engine off - 14.65V with the engine running. I turned the engine off after a couple of minutes and re-tested the voltage; it had gone up to 12.65V. The battery has one of those little round windows that are supposed to go green if the battery is OK. The window isn't green, more black - am I right in thinking that the battery is borderline?

BoroRover · 21st March 2017, 11:32

Quote:

Originally Posted by Mike24

About a month ago my wife moved the driver's seat (electric memory) ready to go shopping, got in the car, but it wouldn't start - flat battery. She hasn't driven the car since, so the driver's seat hasn't been moved. This afternoon I moved seat in order to vacuum the footwell (doesn't happen very often), got in the car this evening to visit friends - flat battery...

The battery was in the car when I bought it nearly three years ago, but, apart from these two occasions, has never given any trouble. I am wondering which is more likely; that the battery is coming to the end of its life; that, somehow, moving the driver's seat is causing a rapid drain on the battery; or neither of the above?

I've just though of another possibility; I've been having trouble lately with the windows not working properly - perhaps its something to do with them?

Any suggestions gratefully received.

Well, the battery looks the likely culprit, but, in case it isn't, one problem I had with a battery drain, the drivers electric seat fuse was the problem. Took an auto electrician to find that one out !! Just a suggestion.

Mike24 · 21st March 2017, 11:35

Thanks for the quick reply; I've had my suspicions about the driver's seat - twice now I've been unable to start the car after moving the seat. Was the problem with yours that the fuse had blown, or was there a bad connection or something?

SD1too · 21st March 2017, 13:00

Quote:

Originally Posted by Mike24

... 14.65V with the engine running.

That's a trifle high Mike.

Quote:

The window isn't green, more black - am I right in thinking that the battery is borderline?

The indicator only tells you the condition of one cell but it should be green. I'd charge the battery externally for 24 hours, disconnected from the car in case there is a drain, and check that the indicator is green afterwards. If it is, the battery is OK. If it isn't, it may well be dying.

Watch your alternator output too. I'd feel happier if it was around the 14 volt mark.

Simon

14th March 2017, 19:11	#1
Mike24 Loves to post Rover 75 CDTI Auto Saloon Connoisseur SE Join Date: Apr 2015 Location: Coventry Posts: 358 Thanks: 166 Thanked 67 Times in 56 Posts	Flat battery About a month ago my wife moved the driver's seat (electric memory) ready to go shopping, got in the car, but it wouldn't start - flat battery. She hasn't driven the car since, so the driver's seat hasn't been moved. This afternoon I moved seat in order to vacuum the footwell (doesn't happen very often), got in the car this evening to visit friends - flat battery... The battery was in the car when I bought it nearly three years ago, but, apart from these two occasions, has never given any trouble. I am wondering which is more likely; that the battery is coming to the end of its life; that, somehow, moving the driver's seat is causing a rapid drain on the battery; or neither of the above? I've just though of another possibility; I've been having trouble lately with the windows not working properly - perhaps its something to do with them? Any suggestions gratefully received. Last edited by Mike24; 14th March 2017 at 19:14..

15th March 2017, 07:57	#2
Mickyboy SERVICING AND DEALER DIAGNOSTICS MG ZT CDTI 135 + & MGZT CDTI AUTO 160 & ROVER 75 TOURER CDTI 160 TROPHY YELLOW Join Date: Aug 2013 Location: Hernebay Posts: 4,331 Thanks: 818 Thanked 2,414 Times in 1,141 Posts	Pop a multimeter across the battery terminals, and check the voltage a good battery will have around 12.6 volts, then with the engine running it should show around 14.2 volts. That way you can eliminate the battery & alternator, obviously you need to get it started first, a set of jump leads or on a battery charge overnight with the battery off the car would be a decent starting point. I'm sure that the ECM won't allow starting below 11.9 volts __________________ [SIGPIC][/SIGPIC] T4 Owner Jobs done : new UBP, Spy hole mod, Rear hub(wheel bearing),plenum cleaned and emptied, Inline thermostat fitted,Full service, In car Digital tv/DVD Bluetooth Satnav etc, Replaced UBP, Restored headlights,Fixed airbag connection.replaced HP pump,replaced rear light seals,changed intercooler O rings. Jobs to do: ,replace drivers lock,.[/SIZE]

15th March 2017, 09:19	#3
Mike24 Loves to post Rover 75 CDTI Auto Saloon Connoisseur SE Join Date: Apr 2015 Location: Coventry Posts: 358 Thanks: 166 Thanked 67 Times in 56 Posts	I've charged the battery over night and put it back on, so the car starts fine at the moment. I am on holiday at the moment (just happened to have a battery charger in the boot!) and will try to buy a multimeter today to test voltages.

21st March 2017, 11:26	#4
Mike24 Loves to post Rover 75 CDTI Auto Saloon Connoisseur SE Join Date: Apr 2015 Location: Coventry Posts: 358 Thanks: 166 Thanked 67 Times in 56 Posts	Having bought a digital multimeter and waited for some fine weather, I've just been out to test the battery voltage; initially it was reading 12.45V with the engine off - 14.65V with the engine running. I turned the engine off after a couple of minutes and re-tested the voltage; it had gone up to 12.65V. The battery has one of those little round windows that are supposed to go green if the battery is OK. The window isn't green, more black - am I right in thinking that the battery is borderline?

21st March 2017, 11:35	#6
Mike24 Loves to post Rover 75 CDTI Auto Saloon Connoisseur SE Join Date: Apr 2015 Location: Coventry Posts: 358 Thanks: 166 Thanked 67 Times in 56 Posts	Thanks for the quick reply; I've had my suspicions about the driver's seat - twice now I've been unable to start the car after moving the seat. Was the problem with yours that the fuse had blown, or was there a bad connection or something?