battery charger

[allanmc]

Ive had a Halfords battery charger for a number of years and as you might know I have been having trouble with my battery draining since June, I havnt sorted that yet but the question today is I removed the battery from the car yesterday and charged it checked it this morning and the reading was 1244v do you think the charger is faulty this was a new battery 3/8/2011
allan

[Gibbo2286]

I don't understand the 1244v bit did you miss out a decimal point?
battery chargers usually have a fuse to prevent damage, it pops if you connect the wrong way round, have you checked?

[Stepto1]

12.44 Volts isn't great for a battery that has JUST come off charge, I'd expect it to be higher. At rest my battery is at about 12.50v and it's not that healthy, easy to flatten. With the engine running it reads well over 13.50v so all well.

Have you checked the fluid levels?
Have you opened the vents before charging?
Is the battery showing any signs of 'bulging' around the sides? If so it's scrap.

[allanmc]

This is a sealed battery and and only 3 months old I think it is the battery charger that is at fault, its one of these chargers with a row of lights which go out when the charge is finished,I made a mistake about the voltage it was 1240v. I thought it should have charged to about 1265v.
allan

[Stepto1]

Get a 'bogo' charger with a proper gauge. You know where you are then. Also a cheap multimeter let's you know where you are with things. To be fair, if you use your car at least once a week you shouldn't need to charge the battery at all. What's the voltage accross the terminals with the engine running?

[Xantidote]

As Stepto suggests, you can't beat an ammeter, rather than a row of lights, but voltages are also helpful. Could be, Alan, that you haven't fully charged the battery? If you have a meter across the battery as you connect the charger, you should see the voltage increase, which will at least tell you the charger is working.

Presently I have a Ring digital voltmeters that's plugged into the cigarette lighter, and it's displaying 12.5v, whereas my cheapo multimeter across the battery reads 12.70v - so which one's right? At least they are indicative. The battery is a new exide, fitted yesterday.

If you had a specific gravity tester, that would also give you an indication of the battery's state of charge.

[Stepto1]

Gauge accross the terminals every time. There is alot of voltage drop on these cars due to corner cutting. You just need to see all the posts re. heater failure, dim headlights, broken electric windows and many other electrical gremlins.

[Gibbo2286]

As I said before check the charger fuse, my charger is one with the row of lights but the lights deceive, they show full charge when the charger is outputting nothing, mine has a ten amp car type fuse in the base.

[allanmc]

Voltage across the battery with the engine running is 13-35volts what I need to know is if the lights on the charger are on can there still be no power to the terminals

[Peter.N.]

Check the voltage across the charger leads without the battery connected, should be about 15 volts.

Peter

[allanmc]

Checked again reading across the batt. with engine running 14.35 the charger that I have you dont get a reading until its connected to the batt. then it reads 14.2 volts sorry about that
allan

[Peter.N.]

If its an old charger you should have a reading of about 15v across it with no battery connected, if not its faulty.

Peter

[Mr Micawber]

Checked again reading across the batt. with engine running 14.35 the charger that I have you dont get a reading until its connected to the batt. then it reads 14.2 volts sorry about that
allan

Those voltages are about right Allan.

Simon.

[Stepto1]

Sounds like the alternator is charging ok and the battery charger is working but isn't the most powerful in the world.

If you're getting 14+ volts while it's on the car, why do you need to charge it?

[Gibbo2286]

If the battery keeps going down within a few days power is leaking away somewhere, boot light stuck on, dodgy aftermarket alarm maybe or some of the Citroen electronics faulty or of course the alternator diodes popped.