Battery Drain

[groomi]

Had this problem for a long, long time on my X308 but not been able to trace the cause. If I don't drive the car for a couple of weeks then the battery goes completely flat. I'm now using the car less and less frequently as work is gathering in London so I get the train more often, so this is becoming more of a problem.

I could do a temporary fix by getting one of those solar panels which plug into the cigar lighter, but I'd rather find the root cause if possible. Anybody come across this before?

[x200sxy]

Is it the battery past it or is it losing charge somewhere?

I have the same problem with my 8 years old Range Rover but can't be bothered to spend any money chasing it, I just jump start it once a week.

[__G__]

Had a similar problem with my x308 the battery going (almost) flat after being left for a few days at a time. I topped up the battery fluids and it seemed to fix off the problem.

I'm by no means an expert but are you sure it's a drain? Did you run a multimeter across the terminals with the engine off? This should also let you know how big the drain is and it may give you some idea as to what's causing it...

Also what voltage across the terminals are you getting with the engine off and when warmed up and (hopefully) charging?

Edited by G on Monday 24th November 13:43

[x200sxy]

Tis a drain, seems to be bewteen 0.5 and 0.8A but no idea where to, no interior lights on or anything like that. Battery is charging absolutely fine.


[quote=G]

I'm by no means an expert but are you sure it's a drain? Did you run a multimeter across the terminals with the engine off? This should also let you know how big the drain is and it may give you some idea as to what's causing it...

Also what voltage across the terminals are you getting with the engine off and when warmed up and (hopefully) charging?

Edited by G on Monday 24th November 13:43

[/quote]

[groomi]

I've had to replace the battery a couple of times in the past three years as it just deteriorates with all the discharging/recharging. The same thing happens with a brand new battery, so it is definately draining.

It's not worth paying someone to diagnose it, but I would like to solve the problem myself if I can just for conveniences sake.

[LondonItalian]

There will be various ECU`s that stay on after the car is turned off even if the car is left unlocked with the alarm off, some of these will be relatively high drain for up to an hour or so, but even after that some will remain on, albeit drawing tiny currents perminantly.

Its not like the old days when you could leave your Viva or Mini standing for 1 or 2 months & still rely on it to start!

All modern cars suffer from this, even down to humble superminis. I`d say 2 weeks is about the max you can expect a car to last before dipping below starting amps & this is amplified if you tend to do few, short journeys that dont replenish the battery fully.

Also, bare in mind that big executive cars place huge demands on batteries & this means that after 2 or 3 years they will be on their way out. The X308`s do have an issue with tired batteries & this can also result in erronious fault codes & warning lights appearing on the dash for no reason.

The solar panel thing would help things, except the cigarette lighters go off with the ignition on the X308 as opposed to say the XJ40, so a slight rewire or a seperate direct link to the battery would be needed to make this work.

Cheers

Edited by LondonItalian on Thursday 1st January 18:26

[steelej]

Get one of these

www.batterybrain.co.uk

I use them on two of my cars that don't get used that often, infra red remote to disconnect and reconnect the battery, very convenient

John

[LongQ]

I had something similar on an Omega a few years ago.

A new battery would be fine for 6 months and then problems would start.

Had several things done but learned to get in and out through the boot in the end since the driver door lock failed to work and the there was not enough power to operate the central locking.

Finally finured that it actually only happened after it havd been raining or otherwise got wet.

Then noticed that one of the scuttle drain holes deposited its collected water into the wing to drain right above the alarm system - on which the protective insulation had shrunk with age.

Further noticed the plastic scuttle trim had cracked a little. Cosmetic I thought until I spotted that the crack meant that water could drip directly onto the contacts of the alarm siren. A nice wetting could flatted the battery overnight by that point.

Some experiments suggested that this was indeed the problem but the car was worth F All and the alarm had started to sound randomly, even when driving, so I offloaded it rather than fix it but my WD40 treatment seemed to work for the interim period and leaving it unlocked (no alarm set) also seemed to eliminate the problem. (And saved my having to climb in through the boot!)

Your problems may be different but maybe this story will prompt some ideas.

[Trooper2]

Groomi, sounds like you either have an alternator on the way out or have a perisitic drain. I.E. some circuit or module isn't turning off as it should, when you remove the key. It could also be that your battery has gotten low in charge and the alternator can't top it off with your normal driving, alternators are for sustaining, not for charging. Disconnecting both battery leads and giving it a proper charge may even cure your problem.

Low batteries, short drives and alternators on there way out can give the symptoms you described...( I just replaced the alt and then the battery on my Land Rover). Alternator failed and failed the tests, battery passed tests but then wouldn't start the truck when it got really cold over night a couple of weeks later, retested the battery with a battery tester meant for Ford warranty purposes and it failed.

The battery was an Optima and was in my Trooper for 9 years and lasted for 2 more in the Landy, just can't expect much from a 3 year battery warranty any more.....

Anyway bad alternators tend to kill batteries and bad batteries tend to kill alternators. If you rule those 2 items out and want to know how to test for a parasitic drain, let me know.

Edited by Trooper2 on Tuesday 6th January 05:35

[Dozzadoes]

I have a problem with a daimler and have a battery drain of .5A to .8A.
A friend of mine has said to check out the electric airial circuit. The relay can stick on, and pull down the battery over a day or two. Battery voltage and charging voltage test out ok untill the battery discharges and falls to about 10volts.Solar panel does not prevent the fault,just delays it.
So isolating the airial circuit is an option to try.Good luck:-)

Edited by Dozzadoes on Saturday 6th June 00:50

Edited by Dozzadoes on Saturday 6th June 00:51

[pr100]

LondonItalian said:

I`d say 2 weeks is about the max you can expect a car to last before dipping below starting amps & this is amplified if you tend to do few, short journeys that dont replenish the battery fully.

My XK8 often sits idle in the garage for 2 weeks and sometimes 3 -- and the majority of my journeys are under 10 miles, hence my annual mileage of approx 1500. But I have never had any battery problem. Starts first time, every time with great eagerness.