Battery goes dead on wet/cold weather?

[siroki]

Hello,

Excuse my English maybe not being very good.

I have a really strange problem with my 325ix Touring, and this only seems to happen when the there is cold weather or if it has been raining.

The other day I drove my car just fine, then it rained and got quite cold during the night. The next morning the car started, but with some difficulties. When I turn the ignition, the engine makes a 'slow' sound and then after like 10 seconds of holding the ignition, the engine finally starts. But then after a couple of days of rain and cold the engine this morning didn't fire up any more. The lights in the dashboard did go on, my windshield wipers work, but it seems the battery doesn't have enough power to fire up the engine.

The strange thing is that it only happens when it's cold or wet. When it's during summertime, the car runs just fine.

I have replaced the battery, all engine cables and sparkplugs etc, a new exhaust system. But still the problem exists.

I don't think it's a powerleak too, because otherwise it would happen on warm days as well right?

Kind thanks for your help.

Glen

[march109]

Unless the rain causes a short I can't see how that would make a difference, however most batteries do loose operational power in cold.

[siroki]

The battery is almost new. What I could imagine is that I could have a powerleak, and in combination with the cold, the battery goes dead quicker?

[mark_i]

Check the quality/viscosity of the engine oil.
Cold oil is more viscous and if old and poor quality will be more difficult for the starter to rotate the engine.

What country are you from?

[siroki]

All fluids have also been renewed during the last checkup.

I'm from Holland.

Thing is that when I hook up to the battery of another car, he starts fine. Then I drive for half an hour. I let the car sit for a few hours and then it starts fine. Only when I let it sit overnight when it's cold and raining, it won't start anymore in the morning.

[town325i]

if the battery is faulty the cold can discharge it get it swaped with another one and see if it does the same thing

[Brianmoooore]

Connect a voltmeter across the battery terminals, both with the engine off and with it running.

[siroki]

The battery is brand new.. What should i see when connecting a volt meter?

[mash320i]

roughly 12v or so with it of, and running about 13-13.5v depending on how good your altenator is!

[JJ26]

Why dont you just disconnect the battery one cold evening and then reconnect it the next morning. If it starts normally you know you got a drainage issue. I would use the car prior to disconnecting the battery to make sure it has a good charge.