440 Flat Batter (Again!)

[Bruce_T]

With regards to checking where the probes go Ill do that.

Im not scared of doing this test and dont think I will...

[jlgrosvenor]

In the link posted by Jim C, I particularly like the idea of testing No. 10, on page 10.


The battery draining itself though it's own case - coooool





From what you have posted already, it is either

1 - the battery is duff - with only 12.02V something is wrong
2 - there is excessive parasitic load causing the battery to suffer though overwork

[Bruce_T]

Ive read my manual and it says it has a 10am fuse so if its too much the fuse will will break thus saving the meter?

I dunno.

The car has only been driven for 5-6 mile a day in stop start traffic so if something is draining it wont be getting charged much...

[jlgrosvenor]

From the sounds of it, in all likelihood the fuse will protect the meter. I was just (this weekend) going to charge my car battery up, and accidently touched the two leads together when the thing was on - someone had left the plug socket on.

The fuse (5A) made a little pop but did a really good job of protecting the charger. Changed the fuse - everyting O.K.


As for the distance, I would have thought that with you alternator deliverying about 14.5V you should be getting enough charge to the battery even if something is draining slightly. It is not the drain whilst the car is on that you have to worry about, it is the drain whilst the alternator is not working that will duff the battery.

I really think you should check the parasitic load. This will tell you for sure if there is something wrong.

[Bruce_T]

Ok.

Where exactly do I put the red probe on the 440?

The chassis leg where the neg earth strap goes?

[jlgrosvenor]

Anywhere grounded should do. The strap you are talking about will be fine. I would have though the engine case would be O.K. as well. Any bare metal nuts and bolts connected to the chassis should be O.K. too.

[Bruce_T]

Its throwing it down with rain now so ill leave that bit till tomorrow.

Thank you for your help, its been invalauable.

[Bruce_T]

I unlocked my car at 7:20am.

Check the battery with the meter and got a reading of 11.56V that was with evertything connected and locked/alarmed overnight

I then thought id try testing the current been drawn. But I did not get anything so I think I was doing something wrong.
Maybe I should lock the car with the bonnet up and re-check.

Anyway, the car would crank just and then stop and click.

I put my jump pack on, started instantly. Checked battery. 14.25V

I then put every electrical thing on in my car, down to 12.65v but with revs soon jumped upto 14+v

Drove to work.

Stopped, checked battery while running 14.6V.
Stopped the car and checked again, I could see the battery voltage dropping in front of me while been tested. Started at 12.6 then 12.57, 12.56 etc etc all.

I thught hm. Took the neg off the batt and it was still dropping! I left it sat 12.31-12.29 ish where it was slowing.

Does this mean the battery is duff? Or its just not been charged enough on the run to work?

[JIM C]

I would put the multi meter back on thw battery at the end of your working day and get a reading before its started up and running. Sounds like the battery.

[jlgrosvenor]

If the battery is disconnected at the end of a run (i.e. after charging) and is showing the 12.6V it should, this shows the alternator is working.

If the battery is then loosing charge whilst not connected to anything, it sounds to me like a duff battery. ****y batteries usually come with a 2 year guarantee. Better brands usually carry a 4 year guarantee. Do you have your receipt?

Did you carry out the cross-case test (No. 10, page 10) in the guide posted by Jim C?