Discharged battery(again)

[Brenda]

Im finally pulling out my hair with my battery discharge problem.

Each and every time I want to use the Volvo I have to jump it,and at this time of year I could do without it.

I put a voltmeter across the battery terminals while it was in a state of discharge and was amazed to see a mere 5volts. Yes 5 volts!!

Have now borrowed a charger from a neighbour who saw me struggling, and the battery has now been on charge for 36 hours. The charger is still pumping out 2 amps, so I hope itll be ok.


Sounds like the alternator to me, any other ideas?


Brenda

[TonyS9]

5v = totally knackered battery. The charging current should have gone down lower than 2A by now. Keeping it on charge 'might' improve it, but it will never be 100%.

Why do you think its the alternator, I don't remember the details.

[Ragamuffin]

Is it discharging with ignition off, doors closed etc?
The charger will keep showing current flow even with a fully charged battery. After 36 hours it will be fully charged by now.

[vjck_uk]

the above are right a battery thats got down to 5 volt isnt much good after usually and most chargers will happily still put amps into a brand new battery,try it with the battery disconnected and see if it still goes flat or you could make sure everything is off and disconnect the red (plus side) terminal and set the meter to amps and usually have to swop one of the test leads then see if its taking any current,if it is taking above one amp try pulling the fuses out one by one which should show which circuit is causing the problem ,if you think it maybe the alternator take off the thick lead to it and if it makes no difference its not the diode pack

[Alasdair1]

I reckon the battery has a bad cell especially if its only reading 5v. Had similar problem. Got battery checked at local Lucas service (alas no more). It used to take charge ok but went flat very quickly especialy if not being used much. It doesn't take much to flatten a bad battery like alarm etc. Also worth checking the battery acid level if its not a sealed unit and another thing is my old 940 had a courtesy light in the engine compartment. Great idea until it started to stay on with bonnet closed.

Hope you get it sorted soon.

Alasdair

[Toplights]

Sorry Brenda,New battery time,they are usually replaced long before they get as low as 5V.

[Brenda]

Youre probably right Toplights, but this one is only a year old.


This problem has been happening for wellover a year now which is what prompted me to buy this particular battery when I did....

[stevo48]

As above, get a meter across the battery while it is in the car then start pulling fuses until you find what is draining it, was it an expensive heavy duty battery when you bought it or a short life cheapo, these Volvo's needa quality battery due to the drl's etc.

[vjck_uk]

not if you turn the drl's off like have

[TonyS9]

Originally Posted by stevo48

As above, get a meter across the battery while it is in the car then start pulling fuses until you find what is draining it, was it an expensive heavy duty battery when you bought it or a short life cheapo, these Volvo's needa quality battery due to the drl's etc.

The drl will make no requirements on the battery, all power comes from the alternator when the engine is running. There are 2 requirements for a battery

1. Starting the engine (turbos have a much lower requirement than NA cars)
2. Running the alarm with the engine off (and occasional running the radio/lights while sitting in the car without the engine)

Any car needs a 'quality' battery. I have had 1 new dud when I bought a replacement for the BMW recently. It didn't last 24hrs, the 2nd replacement lasts still starts the car after 3 weeks parked up.

If you are using the car only occasionally and then on short journeys (say 10mins) it will kill a new battery. Otherwise you have current leak somewhere or the alternator is not charging properly. Charging is easily checked by a voltmeter on the battery when the engine is idling, should be about 14v.