Help needed :Battery goes flat overnight.

[No9]

After replacing the battery yesterday due to being flat that morning and not wanting to take any chances,went to start car this morning and same thing flat as a tack.No battery light came on at all during the day and now there`s not even enough power to run the radio please can anyone shed some light on this .thanks

 

[d.k.vmatt]

Something must be discharging it. Do you have any aftermarket electrical gear in it? Eg head unit, amps ,gauges?

 

[No9]

No car is completely standard.

 

[Beav]

Make sure interior light and boot light don't stay on. Have you got good earth

 

[davleigh]

In my old commodore I had a problem with the little light near the ignition barrel. It just stayed on and ended up draining my battery over nite. Just something else to check in case you haven't found the reason yet

Sent from my GT-I9100 using Tapatalk 2

 

[No9]

Thanks guys ive checked all these things and they seem ok ,i also put a volt meter across the battery terminals when i got the car started and the alternator is putting out 13.99 volts at idle is that normal?

 

[pablo]

I have always worked on inbetween 13.8v - 14.2v as being an acceptable charge rate. You are smack in the middle.

 

[lout]

is new battery actually new and good quality
if no lights are remaining on , glove box, boot
then try disconnecting positive wire from alternator before going to bed and see if fault remains, may be shorted diode in alternator

 

[Oldskool]

Ya alternators stuffed.
Its not charging battery

 

[tezza]

If the alternator is working correctly, put the multimeter on amps and connect it in series and see what the drain is
(making sure ignition is off and doors are closed). that will then tell you if you have something draining the battery or not.