Battery drain, Battery goes flat after a week

[foggy1]

Hi all, I have a 1992 2.1 SED, got concerned when hearing a click when connecting battery, measured drain on battery, about 27ma for 30 secs then drops to 0.9ma, that seems low and about right, but battery goes flat after 1 week, new batt. ,is there a fault or is it OK?
Regards Foggy

[robertmnorton]

Hi foggy,clearly those stated values are too low to cause a new 72Amp hour to drain off so quickly and are probably the alarm aquiescent current.How did you measure the current,clamp meter or by disconnecting the battery negative?
It is more likely something like the boot light,or under bonnet light.Something you can't see.The boot latch light switch really is a cheap nasty design,and with a bulb rated at 5w should show around 400ma,which would give a max battery duration of about 7 days.
There are many other components that could cause similar results,the hydractive electrovalve for example,It just requires a systematic approach to isolation.The click on connecting the battery - a relay energising - is normal.
Sorry if this all sounds a bit vague,hopefully someone that has experienced a similar issue can give a better direction.
robertm

This post has been edited by robertmnorton on October 22, 2010 08:18 pm

[Jan-hendrik]

The drain you measured is OK. You haven't provided a lot of details, e.g. about how the car is used. Something might be wrong with the charging system.

[foggy1]

I think it may be the switch on the transmission lever, doesnt always allow starter to work, how to get at that?
David

[Jan-hendrik]

There is a switch on the back of the transmission. Hard to get at. There is a relay behind the right side head light. The ignition/starter switch may be worn out.

There is a thread on this on 'the other' XM forum. Goto: http://www.club-xm.co.uk/forum/viewtopic.php?f=8&t=1528

But you may have to register

[foggy1]

Thanks for that, Is there an illustration showing the functions/locations of the various relays?

This post has been edited by foggy1 on December 18, 2010 05:59 pm

[Jan-hendrik]

There is a photo indicating the (likely) location of the inhibitor relay.
If you are serious about this you might want to pull all the various relays and check their condition.
Both forums have search functions that may help in finding what you need to know. A bit of 'leg work' is required.
A workshop manual can be downloaded here:
http://www.ebaman.com/index.php/remository...echanical-Part/

[paulstringer]

Similar issue, did you ever manage to find the cause of this? I have a similar sounding issue with drain of 0.7 and good charging voltage in the 13.5v range when running. Regardless though if leave the car for around 1-2 weeks it will struggle to start on a just bought new battery.

One thing I notice is dashboard lighting is noticeably dimmer when applying the brakes. Other possibility is my starter motor failing and demanding too much from the battery when cranking??

[Norman]

I had something similar with my 2.1 td battery going flat after a week of non use starter struggling to turn the engine over, cured by replacing the battery clamps and a new high capacity diesel battery, never a problem after that.

Norman

[paulstringer]

Eliminated the clamps as an issue after having new ones made and fitted last year. Been taking readings after leaving over night. Drops around 0.13v over a 24hr period e.g starting at a well charged 12.5 it'll be down to something like 12.37 the next day. At that rate within 7-10 days it will begin to struggle to start the starter motor - so at around 11.5v. starting performance gets noticeably worse. So thoughts on this welcome is it a) this amount of drain normal should that amount of drop down to 11.5v still be capable of starting. If both are correct then is there more likely an issue with the starter.

On a side note the LED displays noticeably dim when using the brakes.

[Peter.N.]

If the voltage is only 13.5 with the engine running that's your problem, it should be about 14.4, the battery is not being fully charged in fact hardly charged at all, a fully charged battery will only be 13.2 volts so with that voltage difference there will only be a very small charge. You likely need a new alternator although you can probably get a replacement electronics module for very much less money.

Peter

This post has been edited by Peter.N. on August 02, 2016 12:07 pm

[paulstringer]

Checked the level of voltage on this again with engine idling. Getting that reading of about 13.5v still. Guess that would be higher if the engine was running at higher revs. Be good to get something to compare the idling charge to to figure out if the problem is the alternator.

Aside from the alternator though, this isn't a cause of the battery not being able to start the engine after 10 days from a full charge though. Should last longer than that right everything being good?

What's the minimum amount of charge that should still be sufficient to get things moving in the starter motor department.

This post has been edited by paulstringer on August 03, 2016 11:51 pm

[Peter.N.]

Have you charged the battery from an external source and it goes flat, only the battery is never going to be fully charged with that alternator voltage. If the alternator is OK it should be giving about 14.4 volts at tickover once the battery has recovered from the initial start which won't take long.

You can easily check if something on the car is running the battery down, if you have access to a multimeter, switch it to the 'amps' range and with everything turned of, remove one battery lead and connect one meter lead to that and connect the other one to the battery, set it for about 1 amp and check the current flowing, if all is well it shouldn't exceed about 50m/a, if it does try removing one fuse at a time until the current drops, it could be the faulty alternator that's drawing current so I would try disconnecting that first

At 50 m/a it will use a bit over 1ah per day, so if its a 60 ah battery, assuming its a diesel and the battery is in good condition it should stand that for about a month and leave enough to
start it.

Peter