Car battery runs down!

tickman

Firstly i only seem to be asking questions here and never able to answer them so sorry if it is all take take take!

i have a `96 Vectra estate 1.8ls which keeps discharging the battery when left without use some times for as little as 4 days other times it seems to last for weeks without problem! there seems to be no common problems connected, lights off, indicator stalk in the centre and all items switched off. i even took out the radio as this was an after market item and i thought it might have battery drain, but problem persists. the battery is new and all the electrical items of the car seem to work as they should. if you have any ideas i would yet again appreciate all/any help. i have good basic knowledge of electrics and have a good meter with current clamp so can invistigate any ideas. willing to grasp at all straws! should just sell it and walk more but i know i am not brave enough to try and the local transport service is quite poor!
hope someone has some ideas,
T

ariba10

The only thing I can suggest is to disconnect one of the battery terminals and put a meter across the gap to see if you have a leakage.

tickman

what do you mean leakage? what sort of reading should i expect?

do you mean check to see if the connections are poor as this would in itself create a drain on the system? and not just the battery terminals!

T

espresso

tickman wrote:

what do you mean leakage? what sort of reading should i expect?

do you mean check to see if the connections are poor as this would in itself create a drain on the system? and not just the battery terminals!

T

You should only see a very small current flowing out of the battery i.e. a few milliamperes supplying any clock, radio memory, alarm/immobiliser etc. when everything else is switched off.

Poor connections on the battery terminals would not cause a drain on the battery and would be apparent when using the starter motor etc.

It could be something really simple like a glove box, boot light or interior light not switching off properly, which you could check with your meter.

I once had a car where the interior light was supposed to stay on for a few minutes controlled by an electronic timer which failed causing a similar problem to yours.

You should be able to find anything that is drawing current by using your meter with a bit of experimentation but as we are talking small currents, I doubt if a clamp sensor type would be sensitive enough.

If you do disconnect the connection to the battery lead for inserting your meter, ensure that you have any required radio code first!

sicker

If you put your meter across the gap there should be no current flow. If there is a reading it would appear that something is drawing the current from the battery. Are you sure there is no interier light on or something similar?

John.
ps I am no expert and these are just my thoughts from past experience.

tickman

i will check these out, crawl through the car and see if i can find things on that should not be! unfortunatly i will have to charge the battery up first only 2.5 volts left in it! it is a new battery, the old one was past it, probably the battery draining it thing had started!

espresso

A 12V battery should never read that low so it could be faulty!

sicker

Another thought is that just because the battery is new it does not mean it can't be faulty. Could be a faulty cell dragging the rest down. Could you not get a local garage do test it?

John

expresso just beat me to it.

sillybean

Get a new battery, happened to me before, just buy a new battery. Job done. Unlikly to be anything more complicated, they last about 4 years normally as far as i remember from the AA man.

tickman

i will get the battery checked, not even three months old so no problem with getting it swapped if it is faulty.
thanks again.
T

albertross_2

Have you ruled out the alternator not charging it?

If it is not the alternator, and not a faulty battery, you could possibly diagnose which circuit is draining it by checking the current drawn, and pulling out the fuses one by one, until there is no more (or minimal) current being drawn.

I have heard of faulty dashboards causing this problem, but not on Vauxhalls..