Discussion
Took the S out for its pre MOT post Winter warm up blast this evening. Car ran really well considering that it's been sat under its cover on the drive waiting hopefully for better weather.
Voltmeter reads a healthy 13volts at first, but as soon as I turn the dip beam lights on then it drops like a stone into the Red zone. I didn't dare to turn on the heater as I only have fast speed and thought that it would decimate the battery.
My previous S2 was exactly the same on the Voltmeter whenever you turned something electric on it dived into the Red.
As the car alternator is rated at at least 80 Amps and the headlamps take just shy of 10 Amps then surely the alternator should have been able to handle the current draw and more?
So
1/ Is the Voltmeter just giving a wrong reading and I can run the lights, heater, etc with no concerns?
2/ Is my alternator likely to be knackered, unable to handle a 10 Amp load?
3/ Do they all just do that?
4/ Should we all fit a battery charge state Ammeter and ignore the Voltmeter?
Bob
Voltmeter reads a healthy 13volts at first, but as soon as I turn the dip beam lights on then it drops like a stone into the Red zone. I didn't dare to turn on the heater as I only have fast speed and thought that it would decimate the battery.
My previous S2 was exactly the same on the Voltmeter whenever you turned something electric on it dived into the Red.
As the car alternator is rated at at least 80 Amps and the headlamps take just shy of 10 Amps then surely the alternator should have been able to handle the current draw and more?
So
1/ Is the Voltmeter just giving a wrong reading and I can run the lights, heater, etc with no concerns?
2/ Is my alternator likely to be knackered, unable to handle a 10 Amp load?
3/ Do they all just do that?
4/ Should we all fit a battery charge state Ammeter and ignore the Voltmeter?
Bob
Sandgrounder said:
Hi Bob, not sure what reasons is, but I have an S3, and my voltmeter does not do that. Light son,m heater fan running, minimal drop on voltmeter.
Could it be a bad earth??
Hi Graham, thanks for the reply. Are you thinking a bad earth in the gauge connections? Any idea where to look to fix it?Could it be a bad earth??
Bob
SJS357 said:
Have you had her on a trickle charger Bob. ?
I had a similar issue back in October.
Replaced Battery, (was the one that came on the car) it wasnt holding its charge.
After checking everything with a multimeter.
No issues since.
Hi SimonI had a similar issue back in October.
Replaced Battery, (was the one that came on the car) it wasnt holding its charge.
After checking everything with a multimeter.
No issues since.
I had the battery disconnected for the last month or so after fully charging it. Re-connected it on Tuesday and it had plenty of charge to start the car. Left it connected and did about 6 starts with no problem, the last 2 after the run out with the Voltmeter in the Red.
Battery was brand new this time last year, got the top spec Halfrauds one with a 4 year guarantee.
Bob
Hi Bob, this came up quite recently but can't find the thread, maybe it wasn't the title subject?
Mine does the same, think it was coming back from first Eurotour, up the M40, lights wipers and heater fan on and voltmeter didn't look happy!
Switched fan off to help, that was couple of years ago now and never had a battery or charging problem?
Maybe they don't "all do that sir" but I think quite a few do. As has been suggested, I think an ammeter would give a better indication of whats going on?
possibly you're just not using it enough, come and join us for breakfast, Saturday or Sunday
Hi Mike
I might be with you and Simon at Sainsbury's Redditch (was that the one)at 8:00. Subject to getting a years new MOT at Happy Days on Saturday morning and another appointment being cancelled (likely).
I've signed in on the MAC site.
So yes you're right that I'm not getting her out enough...
Bob
I might be with you and Simon at Sainsbury's Redditch (was that the one)at 8:00. Subject to getting a years new MOT at Happy Days on Saturday morning and another appointment being cancelled (likely).
I've signed in on the MAC site.
So yes you're right that I'm not getting her out enough...
Bob
May be similar Bob as the RT guys had the battery discounted
While the work was being done on mine.
Same all worked fine till it just didn't.
We checked the drain on the battery with a meter by starting things and seeing the reductions.
Just proved the bat was loosing its charge.
Turned out to be faulty cells in the battery.
Have you got one to switch or go with the Halfrords swop.
Won't do any halm to refresh to a new one.
Least rules that out.
Simon.
...Just added fingers crossed see you Sunday Bob.
...
While the work was being done on mine.
Same all worked fine till it just didn't.
We checked the drain on the battery with a meter by starting things and seeing the reductions.
Just proved the bat was loosing its charge.
Turned out to be faulty cells in the battery.
Have you got one to switch or go with the Halfrords swop.
Won't do any halm to refresh to a new one.
Least rules that out.
Simon.
...Just added fingers crossed see you Sunday Bob.
...Edited by SJS357 on Thursday 4th April 21:57
Ragtop said:
Have you got a decent multimeter? Measure the voltage across the battery terminals with the lights/heater on/off and see what you've really got...
Good luck,
Graham
Hi Graham, thanks for the idea.Good luck,
Graham
I haven't got a multimeter, but I'm booked into our local friendly garage on Saturday morning so I will ask them to drop a meter over it to see what's happening.
Any idea what would constitute good or bad or what a low reading would show? Knackered Battery or knackered Alternator?
Bob
Hi Bob,
I posted some time back re mad speedo that jumps up + 20-40mph when the engine cooling fan cuts in also my voltmeter drops to less than 12 volts, with headlamps on and heater on first position the voltmeter does the same, I have cleaned and replaced earth leads, fitted a high quality battery last year but still she does the same.
My hand held tester shows 13.6 volts across the battery terminals at idle with no load other than the ignition and 13.2 when under load with heater and lights on.
I have not taken it any further as i try to use my S2 every weekend even through winter, always starts.
Even with the indicators on my speedo bounces up and down in time with the lights flashing.
It could be the voltage regulator which I assume is part of the alternator, like I say it's done this since I took ownership 3 years ago but always starts ok.
I posted some time back re mad speedo that jumps up + 20-40mph when the engine cooling fan cuts in also my voltmeter drops to less than 12 volts, with headlamps on and heater on first position the voltmeter does the same, I have cleaned and replaced earth leads, fitted a high quality battery last year but still she does the same.
My hand held tester shows 13.6 volts across the battery terminals at idle with no load other than the ignition and 13.2 when under load with heater and lights on.
I have not taken it any further as i try to use my S2 every weekend even through winter, always starts.
Even with the indicators on my speedo bounces up and down in time with the lights flashing.
It could be the voltage regulator which I assume is part of the alternator, like I say it's done this since I took ownership 3 years ago but always starts ok.
A fully charged battery should give about 12.6V. If it's 12V or less, it's nearly flat and/or dead.
With the engine running at idle and all electrics switched off, the alternator output should raise the battery voltage to around 14V. If the alternator is sound, I would expect it to maintain at least 13V with the lights and heater on, but not necessarily at idle - it may need an engine speed of up to 2000-2500rpm to provide sufficient output.
It will vary from car to car. A Google should find you more definitive data.
Graham
With the engine running at idle and all electrics switched off, the alternator output should raise the battery voltage to around 14V. If the alternator is sound, I would expect it to maintain at least 13V with the lights and heater on, but not necessarily at idle - it may need an engine speed of up to 2000-2500rpm to provide sufficient output.
It will vary from car to car. A Google should find you more definitive data.
Graham
Bob
Worth testing battery voltage across terminals and then on battery clamps to see if you have a bad connection. If you can test volage on chassis earth pint and battery positive then that may give a clue. If you go to Halfords or any good garage they will test the battery to see if it has had it. Usually a cell which has failed. Not unknown, even in young batteries.
Cheers
Tony
Worth testing battery voltage across terminals and then on battery clamps to see if you have a bad connection. If you can test volage on chassis earth pint and battery positive then that may give a clue. If you go to Halfords or any good garage they will test the battery to see if it has had it. Usually a cell which has failed. Not unknown, even in young batteries.
Cheers
Tony
I didn't get to check the voltage readings at the Garage today as it took ages to do the tank to pump fuel pipe change that was planned, then the MOT.
So if anyone has a multimeter and knows how to use it (Simon?) that's going to Shelsley tomorrow then I'd appreciate the help.
Did a really long crank on the car today getting it to start after the fuel pipe was changed (lead fell off the fuel pump). Anyway it surprised me how long it would crank with no problem. Seems as if the battery was really strong.
On the way home with a fresh MOT (thanks Happy Days) the voltmeter was reading in excess of 13 volts with nothing switched on. Max speed heater only dropped it down to slightly above the white line and heater and lights on full beam at idle only dropped it to just below the white line.
So it seems to be a bit variable then...
The Shelsley Walsh run tomorrow should put some juice into the battery.
Bob
So if anyone has a multimeter and knows how to use it (Simon?) that's going to Shelsley tomorrow then I'd appreciate the help.
Did a really long crank on the car today getting it to start after the fuel pipe was changed (lead fell off the fuel pump). Anyway it surprised me how long it would crank with no problem. Seems as if the battery was really strong.
On the way home with a fresh MOT (thanks Happy Days) the voltmeter was reading in excess of 13 volts with nothing switched on. Max speed heater only dropped it down to slightly above the white line and heater and lights on full beam at idle only dropped it to just below the white line.
So it seems to be a bit variable then...
The Shelsley Walsh run tomorrow should put some juice into the battery.
Bob
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