Battery drain

[endorfin]

Posted in the other forum when this one was down (why does it keep going down anyway) but haven't had a reply yet.

From when I first got my 2.5 TD XM, on starting the car there always felt like there was just enough battery power left to start the car if you know what I mean. It would turn over and you could see the battery weakening then it would fire. Drive it all day and same thing would happen the next day on starting. I put this down to the battery and bought a brand new Bosch with 760 CC amps. It seemed to cure the problem the first few starts but after that its gone the same way as the previous battery. It has just enough power for a single start.

Now that the car has been standing a couple of weeks now, I went to start it today in case ATS want to pick it up tomorrow (see other thread) and it wouldn't start at all. Battery is far too weak to start.

Obviously something is draining the battery while its standing. Anyone had anything similar happen to theirs and did they find out the cause?

[steelcityuk]

Does your car go into hard mode mode 30 seconds after turning off the engine and closing all the doors? I'm thinking along the lines of the electrovalves not powering down, it's a bit of a long shot but not unheard of being cause by the hatch switch going faulty.

Steve.

[Peter.N.]

You can check for standby current with an amp meter connected between one battery lead (removed) and the battery, the drain should be less than 100ma, with nothing switched on and the doors shut, if its much more than that as Steve says, something isnt turning off.

Another possibility is that the alternator has a low output, connect a voltmeter across the battery with the engine running, it should read something over 14 volts, much less and the battery will slowly discharge.

Peter

[endorfin]

When I was having problems with the 1st battery I had the alternator checked and it was showing 14+ volts so it can't be that. I don't have an amp meter just a multimeter?

[Dieselman]

A multimeter will have an Amp scale.

[onthecut]

Just coming from a different angle, if the ammeter reading doesn't give a clue, is it possible that the issue may be a tired starter or poor connection(s) ? If you have a high resistance joint somewhere, the draw of the starter will make it more so as it heats up. The cabling to the starter is pretty crap on the 2.5. Last one of mine, a small coolant leak over time had rendered the main connector tag very furry and horrible. Check also the condition of the cable as it exits the battery terminal -- they seem to go horrible too, as they age.

Mike.