w123 230 CE Battery/ Alternator Advice Please

[nick45]

Hi All,

I replaced the battery on my 230 CE a couple of weeks ago, drove the car once and then garaged it for the best part of a week because of the apalling weather. This weekend the car engine wouldn't even turn over but jump started first go. I drove it around on Saturday, parked up again and yesterday it was the same again - didn't start off the key but jumped straight to life.

I've got the typical dim light/ stereo flicker of an alternator problem (plus an occasional squeaky belt) but does this sound like something else is draining the battery to you? I'm thinking that a new battery should have been OK to be left for a week regardless of issues with the alternator but perhaps that's my ignorance. Would alternator problems kill a new battery that quick?

I'm grateful for any advice. I'm feeling positive today because my dodgy rear window turned out to be a bad switch, not a failing motor/ mechanism. Tell me the worst

 

[eric242340]

Its very simple to check the charging rate with an ohm meter, ask any garage to check and it should be charging at around 13 volts. That would eliminate the first item on your agenda.

 

[nick45]

Thanks Eric - my difficulty is getting to a garage as I work the same hours they do! I'd still be grateful if anyone else could tell me their experience of this sort of problem.

 

[eric242340]

Thanks Eric - my difficulty is getting to a garage as I work the same hours they do! I'd still be grateful if anyone else could tell me their experience of this sort of problem.

You could do it in your lunch hour, its a 2 miniute test.:idea:

 

[nick45]

The car doesn't come to work with me alas.

 

[television]

These things are not this simple, for a start the battery must be charged to max capacity,then joined to the car. the car needs to be run and then stopped. To place an ammeter in series, this must be done without breaking the circuit otherwise the leakage path could be lost.

Malcolm

 

[eric242340]

These things are not this simple, for a start the battery must be charged to max capacity,then joined to the car. the car needs to be run and then stopped. To place an ammeter in series, this must be done without breaking the circuit otherwise the leakage path could be lost.

Malcolm

Hi Malcolm, at this stage I was not talking abut leakage, but simply checking the charging circuit. ie does the alternator give the correct charge.

 

[Hibbo]

Get a volt meter and put it across the battery.

With the engine off it should be just over 12v.
Start the engine and when revved it should rise to about 14v.

PS. Why did you replace the battery?

 

[jibcl500]

do the dash lights or headlamps get brighter if you rev the engine.

jib

 

[television]

Hi Malcolm, at this stage I was not talking abut leakage, but simply checking the charging circuit. ie does the alternator give the correct charge.

Alternators are not designed for charging flat batteries, if you persist in this you will damage the alternator. The alternator is designed to keep the battery in the leveled off section of the storage curve. Flat batteries should be charged with a charger.

Malcolm

 

[nick45]

Ok folks, thanks for your comments. I've replaced the battery again (I convinced the suppliers it was faulty) & managed to borrow a volt meter. The alternator is showing a charge of 13.49 with the engine on, which drops to just under 12 with heater/ hrw/ lights etc all on. I thought 13.49 was pretty good although you think maybe not Hibbo?
I also did the test where you check for a drain with the engine off and that came back zero so to be honest, I'm not much further forward...
For now I've taken to disconnecting the battery every night but as you'll appreciate, this isn't ideal.
What do people think based on these volt meter results?
Cheers Nick