Current Draw.

[Robflocar]

When at rest, key turned off what current draw do you get. Mine has .05 amps is this normal?. The battery is always flat if I don't use the car for a few days. Replaced the battery with the same result. If this is high then I guess I'll have to start pulling fuses.

[Homestar]

A 50mA draw shouldn't flatten the battery than quickly - should get weeks or more at that. Is the battery ok - or did you mean .5 amps (500mA)?

[Robflocar]

A 50mA draw shouldn't flatten the battery than quickly - should get weeks or more at that. Is the battery ok - or did you mean .5 amps (500mA)?

No definately 50mA. My old battery did the same and now a new battery. I am not sure what the various on board computers might do when left to there own devices. But that is all that I have ever measured. Perhaps I should try another meter. I have an analogue multi meter, perhaps it's time to drag that out. I have never been keen on digital meters so kept the old analogue meter for just an occasion like this.

[Tombie]

Are you locking it each time you leave it?
Was it an SLS vehicle now on coils?
Any USB ports etc fitted permanently (always on) in the vehicle?

50mA is nothing.

[Tins]

Do the doors lock normally with the fob? Mine had a faulty receiver in the roof which drained the battery.
Where are you measuring the amperage?

[Bohica]

A 60 Ah battery will last for 500 days at 50mA per day.
What else is on?

[AndrewMilne]

0.05 Amp continuous draw amounts to 0.05 x 24 = 1.2 Ah per day.
(There is no such thing as 50 mA per day, it is 50 mA continuously for a day.)

This suggests that a 60 Ah battery should last for (60 / 1.2) = 50 days.

It seems that something may be wrong with your current reading, or something else is happening.


When at rest, key turned off what current draw do you get. Mine has .05 amps is this normal?. The battery is always flat if I don't use the car for a few days. Replaced the battery with the same result. If this is high then I guess I'll have to start pulling fuses.

[drivesafe]

When at rest, key turned off what current draw do you get. Mine has .05 amps is this normal?. The battery is always flat if I don't use the car for a few days. Replaced the battery with the same result. If this is high then I guess I'll have to start pulling fuses.
Hi Rob, how much drive time are you doing?

Not using any vehicle much and doing lots of short drives, will have your battery slowly discharging itself and it will be sulphating pretty quickly.

A heavily sulphate battery will hold far less capacity and this will lead to the battery self-discharging in a short time, regardless of how small a load may be.

You may need to rejuvenate your battery with a battery charger.

[Robflocar]

Are you locking it each time you leave it?
Was it an SLS vehicle now on coils?
Any USB ports etc fitted permanently (always on) in the vehicle?

50mA is nothing.

has air bags but used to have coils. The Slab has been changed to show airbags. No USB ports. Not locked in the garage no.

[Robflocar]

Hi Rob, how much drive time are you doing?

Not using any vehicle much and doing lots of short drives, will have your battery slowly discharging itself and it will be sulphating pretty quickly.

A heavily sulphate battery will hold far less capacity and this will lead to the battery self-discharging in a short time, regardless of how small a load may be.

You may need to rejuvenate your battery with a battery charger.

It is true that some of my drive times are shortish. Down into town perhaps 3 km and back. I have to use a battery charger to get it started although it will jump start. I checked with the analogue meter and it is accurate and shows 55 mA. The volts according to Nanocom are 14.4 when the engine is running. The battery was reading only 8.6 volts when I tried to start it yesterday. Perhaps there is not many amps coming from the alternator. Guess that is the next check I'll have to see where that can be done and find a big enough amp meter. I guess these alternators put out a big amount of amps when required. The other thing is that while the battery is larger than most it doesn't fill the battery box there is still a couple of inches of space. I could fit an isolation switch and then reset the radio code and clock each time. But that doesn't fix the cause.

[Robflocar]

Do the doors lock normally with the fob? Mine had a faulty receiver in the roof which drained the battery.
Where are you measuring the amperage?

Doors lock and unlock normally with FOB. Measuring amps at the battery.

[drivesafe]

It is true that some of my drive times are shortish. Down into town perhaps 3 km and back. I have to use a battery charger to get it started although it will jump start. I checked with the analogue meter and it is accurate and shows 55 mA. The volts according to Nanocom are 14.4 when the engine is running. The battery was reading only 8.6 volts when I tried to start it yesterday. Perhaps there is not many amps coming from the alternator.
Hi again Rob, I doubt that there is anything wrong with your alternator.

If the your alternator was not able to put out a high enough current to meet demand, the voltage would have been in the low 13v area.

The fact that it was 14.4v would indicate your alternator is fine but your battery is not drawing much current.

Again, this would most likely be because your battery is badly sulphated.

Have a look at the LONG TERM BATTERY MAINTENANCE section on the link below.

This should fix your problem.

On-Line auto electrical info (https://www.aulro.com/afvb/the-verandah/246755-line-auto-electrical-info-8.html)

[Tombie]

has air bags but used to have coils. The Slab has been changed to show airbags. No USB ports. Not locked in the garage no.

May be your issue.

Modern vehicles until locked don’t shut down completely.

[Robflocar]

May be your issue.

Modern vehicles until locked don’t shut down completely.

I'll try locking it and see if the current draw drops down.

[Robflocar]

Hi again Rob, I doubt that there is anything wrong with your alternator.

If the your alternator was not able to put out a high enough current to meet demand, the voltage would have been in the low 13v area.

The fact that it was 14.4v would indicate your alternator is fine but your battery is not drawing much current.

Again, this would most likely be because your battery is badly sulphated.

Have a look at the LONG TERM BATTERY MAINTENANCE section on the link below.

This should fix your problem.

On-Line auto electrical info (https://www.aulro.com/afvb/the-verandah/246755-line-auto-electrical-info-8.html)

Read this and decided to charge the battery everyday for a week as suggested. Allowing it to do its own thing at night when I usually turn off the power to my workshop at the switchboard. Will await the results.

[Robflocar]

Forgot to put the battery on the charger and after 2 days, flat again. The battery doesn't fill the battery box and is 18 months old, so off to the auto electrician. He said 50mA might be right for this vehicle and so I decided to buy a new battery that filled the battery box. It is 50 mm longer and 5 mm wider. So I'll see how long that lasts. 1000 cranking amps and normally fitted to diesel tractors. The V8 turns over all right now but I'll give it 3 or 4 days and see whether it still will. The old battery load tested as being ok but was on a charger all night as well as a 10 km run before the test.