Car not starting with 9v

Josh_4000 · 23 Oct 2017 at 19:29

Hello on Sunday i went to start my car and it just died like the battery was flat (i had to reset the date and all that) but came back on with out cranking, so i checked the voltage on the battery and it had 9.78 volts in the battery so i gave it another go trying to start but same thing. so i charged the battery to 12 volts and it started right up. so i checked the battery again and got 14.68 volts( this number is higher as the alternator is charging the battery )

long story short i was wondering if this is a sine of bad starter or bad electronics?
car is a Peugeot 206 tu1jp (hfx)

Thanks Joshua

bainbridge · 23 Oct 2017 at 19:37

After a run wait until the engine has been off for 30 mins and check the battery voltage. If below 12.25 volts the battery is poor and should be replaced. Under 10 volts is very poor.

Josh_4000 · 23 Oct 2017 at 19:41

bainbridge said:
After a run wait until the engine has been off for 30 mins and check the battery voltage. If below 12.25 volts the battery is poor and should be replaced. Under 10 volts is very poor.

Ok i'll try this tomorrow

thanks

Rich1988 · 24 Oct 2017 at 13:59

either you left something on in the car or the battery is dead, 14 + volts is what it should be when the alternator is charging so it suggests that is fine, 9v is deader than dead for a 12v battery. It should be around 12.8v fully charged at rest.

Armageus · 24 Oct 2017 at 14:05

bainbridge said:
After a run wait until the engine has been off for 30 mins and check the battery voltage. If below 12.25 volts the battery is poor and should be replaced. Under 10 volts is very poor.

In particular the leaving it 30 mins part is important, as this allows for the "surface charge" to decay which can otherwise provide an inaccurate reading.

Rich1988 said:
It should be around 12.8v fully charged at rest.

Varies by battery, but normally above 12.6V is regarded as fully charged.

bimbleuk · 24 Oct 2017 at 14:34

A lot of modern ECUs won't try to start with ~9V or less voltage.

Daaaavvveee · 24 Oct 2017 at 14:36

Josh_4000 said:
car is a Peugeot 206 tu1jp (hfx)

There is your issue right there!

Dogbreath · 24 Oct 2017 at 15:56

Josh_4000 said:
Hello on Sunday i went to start my car and it just died like the battery was flat
...
so i checked the voltage on the battery and it had 9.78 volts

No 'like' about it, the battery was dead. Could be several reasons:

1) You'd not driven the car for a long time. There is a continuous drain even with the ignition off, so the battery will discharge over time
2) You'd left something on, e.g. side lights, phone charger etc.
3) The battery is dying. They often tend to self discharge very quickly at the end of their life.

Josh_4000 · 25 Oct 2017 at 02:49

Daaaavvveee said:
There is your issue right there!

Haha ture
____
To day before starting car got a reading of 12.72 so I'll keep an eye on battery but if it's holding that it should be fine, I'll put low battery to recent cold weather and leaving head unit face plate in

Thanks to all that have devoted time to help