Hi all. Need some help on this one. I have had 3 disco's over last 15 years and lots of battery replacements cos of drainage on them all. Had a similar thing on my 03 TD5 this winter. Bought a new battery but connections were arse about. Removed the main earth to try and extend cable a bit but no joy. Refitted as was. Car started next morning after heavy frost. Have now decided that it cant be battery. Have looked through posts on this but cant find any with same issue. What I have noticed is that when I lock car off the fob the lights flash and all appears ok. Sometimes a click / clunk can be heard about every 7 - 10 secs. These are the times when car battery drains. If this noise is not present then it will start the next morning. Any thoughts?

Hi, that clicking thing is quite common, happens on many of them and on some not also it's random , IMO it's not the main issue cos the SLABS ECU stays under power by factory up to 1.5 hour and those are some strange "passenger" currents which are exciting the solenoids in the ABS modulator, it's so common and doesnt drain down the batteries on others

you should check the drain after the car stood for let's say 2 hours but leave the bonnet opened cos if you unlock it or open any door the SLABS will become active and you can't see the real parasitic drain

while the SLABS is under power(up to 1.5 hour after ignition was off) the drain can be up to 150mA in some cases even more but then it must drop to around 50mA or below...so measure the parasitic drain as i said and if you get more than 50mA(0.05A) after more than 1.5 hours without activating the SLABS you must find the parasitic drain.

Thanks for the reply. What I don't understand is the battery drain only happens when that clicking can be heard. On times that the clicking is not heard the car fires up the next day like its got a new battery.

So let's not mix things then, maybe we are speaking about different "clickings" 1. is your car on air, converted to coils or original coiler?
2. do you hear those clickings from the ABS modulatior area or where from?
3. what AH/CCA battery yu have and how old it is?

Hi. Car has coil conversion (I believe as it is definitely on coils but has a suspension height adjustment button that does nothing). Also intermittently I get an warning tone and ABS, Traction control and I believe, the hill decent lights come on. Turn ignition on and off and the majority of the time this clears first time. Don't want to confuse the issue but wondered if this could be anything to do with it.
The click / clunk is quite loud and have been unable to identify where its coming from. Appears to be in engine bay but as its intermittent, its difficult to get it to replicate. The noise also does not seem to start as soon as the car is locked. As a dirty smoker, I smoke in the garage and open the door. That's when I noticed the noise coming from my baby outside.
Car has a 750 cca battaery.
Cheers

if it has coil conversion was the whole system removed?,, i mean the compressor and sensors?...check this out and if the sensors or valve block/compressor are still plugged disconnect everything...if they were removed/disconnected answer entirely to question 3 from my firs post cos 750CCA is not the best anyway and the normal SLABS draw which can be variable can drain down a weak battery

Cheers. Will investigate.