S1 battery not lasting

[woody]

Firstly, yes the car is alive, MOT'd, taxed and has been used most days for the last couple of weeks.

However, it has taken to killing batterys. The first was an 18 month old battery that had been left for most of that time with zero charge. Once jumped, the car would run fine with lights & heater on and have enough charge to start the car again soon after, rulling out the alt.

I fitted a new standard 063 on Thurday of last week. It's worked fine until I went to leave this morning after a night at -4C.

Is this likely to be caused only by the weather or an underlying electrical issue? I don't like things with wires

On the plus side, nothing else has broken

Proof:

[neil]

There must be something draining it. The weather might not have helped things but it should still last way longer than that

[robin]

Check your brakes lights aren't staying on ... common problem.

After that you would need a current clamp or inline ammeter and then start popping out fuses until the current drops, assuming it's more than a few milli-amps to start with, that is.

Cheers,
Robin

[jimbo]

Mine was only drawing 1.8amps from the immobiliser when the AA came out last week. He said there was nothing draining my battery, and that I should last for weeks without going flat, regardless of the temp. Reckons that the battery is just pretty crap/faulty and suggested that a Bosch replacement might be a better bet. So annoying!

Sent from my TITAN X310e using Board Express

[woody]

Brake lights are not staying on; had enough of an issue to get the centre one on in the first place.

Think I have a meter somewhere.

The car is immobilised, but the alarm isn't working just now. I damaged the loom at the boot switch (and brake light) using a certain method to gain entry to the boot. Worth checking the alarm circuit first?

[neil]

Mine was only drawing 1.8amps from the immobiliser when the AA came out last week. He said there was nothing draining my battery, and that I should last for weeks without going flat, regardless of the temp. Reckons that the battery is just pretty crap/faulty and suggested that a Bosch replacement might be a better bet. So annoying!

Sent from my TITAN X310e using Board Express

I presume you've got a decimal point in the wrong place. (According to google) an 063 battery capacity will be about 44 amp hours so with a 1.8amp draw from your immobiliser it'll be flat in just over 24 hours.

[robin]

Brake lights are not staying on; had enough of an issue to get the centre one on in the first place.

Think I have a meter somewhere.

The car is immobilised, but the alarm isn't working just now. I damaged the loom at the boot switch (and brake light) using a certain method to gain entry to the boot. Worth checking the alarm circuit first?

Check in any order you like ... preferred method is to wire in the meter with clips or twiddled bared off wire and then leave in mA mode. Don't turn the ignition on - even without the starter the current draw will overwhelm your meter and probably blow a fuse inside it. With ignition off and all fuses in and having waited for the auto immobiliser to cut in check the reading on the meter. Now start to pull and replace fuses, checking the current draw on the meter in each case. It will go to near zero when you pull the offending fuse.

Cheers,
Robin

ETA - when I say zero I mean about 10-100mA I think for the normal alarm/immob function.

[woody]

Brake lights are not staying on; had enough of an issue to get the centre one on in the first place.

Think I have a meter somewhere.

The car is immobilised, but the alarm isn't working just now. I damaged the loom at the boot switch (and brake light) using a certain method to gain entry to the boot. Worth checking the alarm circuit first?

Check in any order you like ... preferred method is to wire in the meter with clips or twiddled bared off wire and then leave in mA mode. Don't turn the ignition on - even without the starter the current draw will overwhelm your meter and probably blow a fuse inside it. With ignition off and all fuses in and having waited for the auto immobiliser to cut in check the reading on the meter. Now start to pull and replace fuses, checking the current draw on the meter in each case. It will go to near zero when you pull the offending fuse.

Cheers,
Robin

ETA - when I say zero I mean about 10-100mA I think for the normal alarm/immob function.

Dug out a meter I remembered having, worked my way around the fuses, and of course it was the last one; the alarm & interior lamp. Went from 1.4 something's to zero.

Interior lamp isn't switching on with the door open either, so may be that.

[robin]

1.4A or 1.4mA???

[woody]

The meter was set at .200u. I decided a long time ago I didn't like electricity and spend some time forgetting everything I knew about it.

[robin]

200u would imply 200 micro amps at full scale and a reading of 1.4 would thus be 1.4 micro amps.

I am doubtful that is actually what you measured as it less than the self discharge rate of the battery!

Send me a picture of your multimeter with the selector dial set as it was when you did the measurement and also with the probes in the same holes ...

Cheers,
Robin

[Ferg]

no help, but great pic!

[woody]

200u would imply 200 micro amps at full scale and a reading of 1.4 would thus be 1.4 micro amps.

I am doubtful that is actually what you measured as it less than the self discharge rate of the battery!

Send me a picture of your multimeter with the selector dial set as it was when you did the measurement and also with the probes in the same holes ...

Cheers,
Robin

I should have your email somewhere but can't see it, just uploaded the pic instead.

[Lazydonkey]

i have nothing to add to this thread other than shouting

SHED

and laughing a lot at the problems caused by your "aircraft spec boot lid stay"

[robin]

Hi Woody,

Well either you had no current draw at that moment or there is something wrong with the way you are doing the measuring.

A 44Ah battery will provide 1mA for 44,000 hours, roughly, and you measured way less than that (it really sounds like you measured 1.4 micro amps, which the battery would provide for millions of hours).

Assuming on the 10A scale it will measure down to 100mA (it will probably display 00.1 for this) and given 100mA is borderline OK current draw (440 hours = 18 days) I suggest you move the red probe to the 10ADC socket and select the 10A scale. Now to test it does something sane you should be able to turn on the side lights (NOT THE HEAD LIGHTS) and you'll see somewhere between 3.00 and 6.00 I think.

Assuming you get that working, then switch off the head lights and post up what the reading is when everything is off, all fuses in.

Cheers,
Robin