Hi I´ve got a BMW 325i sport and I´ve been having this problem, battery goes flat after a day. I´ve installed a new battery and it happend again, heard a noise near the abs system, relays going off. Has any one got an Ider what it could be.
Help would be appreciated.
Ernesto
2007-12-02 23:21:38 · 10 answers · asked by ernesto s 1 in Cars & Transportation ➔ Maintenance & Repairs
The battery in any car needs a constant top up charge from the alternator. It sounds like the alternator is not giving the right output to keep the battery charged.
The simple test is to connect a volt meter to the battery terminals, with the engine running you should have a reading of above 13volts. If you have lower then its time for a new alternator.
Don't get one for BMW as it will cost a fortune, as at Halfords for a service exchange unit. Expect to pay around £120 for the alternator.
Ja.
2007-12-02 23:49:16 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Hi,
Something must be draining the power or it could be a short circuit.
Make sure you turn everything off (even if it's supposed to go off with the ignition).
Get a multimeter and test the battery whilst connected to the car, then remove the earth terminal from the battery and see if there is a difference.
If there is, then something is draining your battery.
If this is the case, check it checked out as a short circuit could start a fire.
I'm assuming the battery is flat when you go to start it in the morning?
Does it charge up when driving?
If not, then it could be your alternator.
This can be checked with a multimeter,
before you start the engine the meter should read around 12 volts,
once the engine is running, the meter should read around 13.5 volts (any more than 14v & you could be frying your battery).
If it is less than 13.5 volts then your battery isn't charging properly & you need to get your alternator checked.
Hope that helps
Danny
2007-12-02 23:32:48 · answer #2 · answered by Danny 4 · 0⤊ 0⤋
Even if your alternator was faulty. ie. not working your NEW battery should not be flat within a day unless you spent all day trying to start it or left the lights on for a long period of time. I would suggest you have not bought the correct battery for your car. Check this out with a garage and replace with the right amphour battery.
Alternatively check that it isnt your starter giving you the impression your battery is flat.
2007-12-02 23:35:15 · answer #3 · answered by Muzikman 5 · 0⤊ 0⤋
After installing the new battery, you need to make sure your alternator is charging the battery at a voltage of 14 volts or so. Simply connect a voltmeter like the one below across the battery terminals while the engine is idling. Set the meter scale to 20 volts DC and see if the meter reads about 14 volts. If the charging voltage is ok, then you need to do a "parasitic draw" test (see link below).
http://www.sears.com/shc/s/search_10153_12605?keyword=digital+multimeter&gobutton.x=0&gobutton.y=0&gobutton=find
http://www.wikihow.com/Find-a-Parasitic-Battery-Drain
2007-12-02 23:32:43 · answer #4 · answered by bobweb 7 · 0⤊ 0⤋
Well you might need a bigger battery since your car is using more energy then the battery has. Also if you bought the BMW between 5 years it is free to take it in to check out what the problem is. If you do not know how to fix things on a car you might end up messing it up more and costing you more.
2007-12-02 23:25:40 · answer #5 · answered by Coop 4 · 0⤊ 0⤋
Faulty Alternator.
2007-12-03 10:24:42 · answer #6 · answered by Anonymous · 0⤊ 0⤋
Chances are that the battery is not getting charged properly. Suspect that the new battery has had little time to get full.
You need to TURN off all electrics not necessary, especially the heated rear window and driving lights when they are not necessary.
2007-12-02 23:31:31 · answer #7 · answered by John B 4 · 0⤊ 0⤋
Sounds like its not holding the charge, which suggests an alternator problem.
2007-12-02 23:24:12 · answer #8 · answered by Sal*UK 7 · 1⤊ 0⤋
I had a similar problem a couple of years ago. It was a problem with the alternator.
2007-12-02 23:32:04 · answer #9 · answered by Spike 2 · 0⤊ 0⤋
Sounds to me that your alternator is shot, take it to your local garage they will be abel to advise you.
2007-12-02 23:24:15 · answer #10 · answered by Les T 3 · 0⤊ 0⤋