HELP Circuit impedance 260E 1988 European model

[cc260E]

This morning after a humid night my battery was flat.
found battrey dry and after filling with adequate water and new recharge, works good.

I have measured the impedance of the car circuitery (without the battery ) found +/- 15ohms, this seems to be a bit high.

Did any body made the same measurement, what is spec value?

I want to check that the battery has not been emptied by a leaking device.

[stevebfl]

I'll have to go drag out my laplace transforms, but I think impedance is like resistance in a dynamic RLC circuit.

I can tell you it has no use doing what you are asking. The resistance of the car would most likely be the resistance of some transistor circuitry it surely wouldn't be dynamic with the battery out of the circuit.

[cc260E]

Originally posted by stevebfl
I'll have to go drag out my laplace transforms, but I think impedance is like resistance in a dynamic RLC circuit.

I can tell you it has no use doing what you are asking. The resistance of the car would most likely be the resistance of some transistor circuitry it surely wouldn't be dynamic with the battery out of the circuit.

You are right, I meant resistance.

I wanted to check how much current was drained by the whole circuitery with everything off.

[cc260E]

Indeed that is exactey what I want to do, in odrer to find what is drainig too much current when every hing is off. ( at this momet my battrey is fllat after 50 hours ( ie +/- 1 amp drain current)

[tecqboy]

The general culprit for a 1 to 2 amp current drain seems to be either a CD stuck in the CD changer ( if you have one ) or the truck lamp or hood lamp remaining on after the aforementioned item is closed. Don't dimiss the possiblity of a battery which self discharges. The best way to test a battery is to measure the specific gravity. An auto parts store should have a cheap device to do this. If the battery was dry and you only added distilled water, the acid may be too weak. ttt

[cc260E]

Thanks to all,

I filled up the battrey with water, recharged it and since one week no flat battery problem anymore.

It happen to be that I may have forgotten an interior lamp on (I may have been sleeping to not have seen it before).

Nevertheless, I measured the resistance with an usual multimetre twice: once with the red lead to the (+) cable and second on the (-) cable. The value are completely different and when I tried to switch on the lamp I suspected it gave the reading of +/- 15 ohms on both ways.

May be it may help in the future.