Trying to trace my battery drain..... story so far (advice needed!)

[Spooky]

So i have had problems with something draining my battery. Just bought another new battery and before i go as far as a new alternator as well, i thought i would check to see if anything is draining the battery.

I found this guide which seems straight forward to follow http://www.wikihow.com/Find-a-Parasitic-Battery-Drain

Followed it as far as step 4 and this is what my multi-meter is showing....



Is this is a good reading or a bad reading? Have i set the MM correctly? I had the -ve side directly on the battery and the +ve side on the cable.

Any advice would be good

[t5 pete]

Very little drain there have you tried pulling the interior lighting fuse and see if it drops I had a drian on the gul it would take 3 to 4 days to drain and was the glove box light I set my phone to video and recorded it with the glove box shut and occasionally the light would flicker put a pad on the glove box lid where it touches and hey presto

[stribo]

You've set it to amps, click round to 200m, that'll give you a reading up to 200 milliamps.

[Spooky]

You've set it to amps, click round to 200m, that'll give you a reading up to 200 milliamps.

Thanks Stribo, I only set it to amps because that guide told me to. Is that not correct?

[stribo]

Thanks Stribo, I only set it to amps because that guide told me to. Is that not correct?

Sorry, yes you are correct, I thought they'd set it to milliamps in the guide. One thing to try is locking the car with the key rather than the remote. When I lock my C70 with the remote, the battery lasts about 3 days without use, if I lock it with the key, it'll last weeks without use.

[Harvey]

Your reading looks OK to me. there's always going to be something if the cars sat waiting for a unlock signal.

[Spooky]

cool! so its more than likely the alternator thats goosed then! that sorts that one out LOL

[Harvey]

What voltage do you have with the engine running at the battery after 5 mins running ? .

[oblark]

You've set it to amps, click round to 200m, that'll give you a reading up to 200 milliamps.

And stand well back ready for the multimeter to go POP.

Voltmeters go in parrellel
Ampmeters go in series.

How I found my battery draining fault was.

1. remove battery from car
2. connect a battery charger to the battery terminals
3. switch on battery charge and see if the ampmeter moves
4. if it climbs to above 2 amps
5. remove one fuses at a time and watch the battery charger amp meter to see if it drops if not refit fuse and go on to the next fuse
6. keep doing this until you find the circuit that is draining the battery

In my case it was the outside temp sensor, unplugged and all ok

[Spooky]

What voltage do you have with the engine running at the battery after 5 mins running ? .

how would i test that Harvey?

[Harvey]

how would i test that Harvey?

Refit battery clamps as they were.

Change meter to 20 dc volts make sure you move the test leads back to volts sockets ,then black lead to negative 0 volts post on battery ,red lead to positive post on battery see what you have before you start the engine make a note what voltage you have .
start the engine see what you have just after starting then leave the engine running for 5 mins and see what it settles at. Running you should see 14.5 to 14.8 volts is.

Then after 5 mins see what you have with no loads on Eg lights,heater motor,rear window heater all OFF take a note of what you have.
,then turn the loads ON leave on for 5 mins engine running still and see what voltage you are running after this time.

[Spooky]

Refit battery clamps as they were.

Change meter to 20 dc volts make sure you move the test leads back to volts sockets ,then black lead to negative 0 volts post on battery ,red lead to positive post on battery see what you have before you start the engine make a note what voltage you have .
start the engine see what you have just after starting then leave the engine running for 5 mins and see what it settles at. Running you should see 14.5 to 14.8 volts is.

Then after 5 mins see what you have with no loads on Eg lights,heater motor,rear window heater all OFF take a note of what you have.
,then turn the loads ON leave on for 5 mins engine running still and see what voltage you are running after this time.

Thank you so much Harvey... only just read this... will give it a whirl in the morning and report back

[Spooky]

Ok so here are the readings....

All off 12.67
Just started 13.88
After 5 mins with nothing on 13.88
After 5 mins with everything on 12.91
After 5 mins after turning off 11.08
After a further 5 mins 12.45

Never hit over 14v at any time.... are these readings ok or is there a problem with the alternator given the drop with everything on and after turning off?

[Harvey]

Looking at these numbers I would get the alternator tested you could have a dead diode inside it,try taking the output voltage from the power output post on the alternator.try taking the rpm to 2.5k and see if the output comes up to more like 14.5 volts
A workshop can test it for you in 10-15 mins easy.

[Spooky]

cheers Harvey and thanks for all your help... you are a star

[LeeT5]

Two things;

1. An amp drain that is above 0.20A is considered a parasitic drain, anything below that is ok. The reading you had of 0.06A is more than acceptable and most likely an alarm module.
2. Charge voltage at the battery should be between 13.5 - 14.5v (as a rule). Anything higher is overcharging and/or battery fault due to the charge voltage not able to stabilise. Alternator output should always be checked 'under load' ie, with rear window heater or headlights on. Should be above 13.5v and not more than 14.5v.

Note: a faulty car battery can and will cause spurious readings on a volt meter - so be cautious.

Do the same test again, this time don't overload the charge circuit by turning everything on. You only need one consumer on to test the charge rate. If it's 13.88v then that's perfectly fine!

You should be seeing charge voltage of above 13.5v withing 20 seconds of starting. It should also be stable and not fluctuate more than 0.20 of a volt.

[Spooky]

Will do Lee.... the battery is brand new at the moment though. the other one was totally fubbard due to having to constantly charge it LOL. This one is not even a week old yet