Bmw 320i touring 2007 wagon

[GUNSMOKEJAE 0]

I had a battery doing weird things 

when tested the battery itself not connected to terminals 

reads 12 to 12.1 volts 

while connected to terminals 

reads 

11.8 volts 

now when I try start 

the car wouldn’t turn over or anything so I tried jump starting via connections in engine bay 

no success 

so I jumped from battery directly in the boot 

the engine would crank but wouldn’t start again and would just wind over and over slowing down the longer I tried to crank it over 

I then checked the fuses 

fuel pump relay 

etc 

fuses are fine 

so I replaced the battery 

with a brand new battery now in the car still only cranks and won’t fully start properly 

just keeps winding over until I press start/stop button to turn car off ignition phase ????? 
 

is this a computer reset issue ? 
where I have program ECU with key to new battery as it’s (for some reason) not registering that a new battery has been connected ??? 

[NZ00Z3 186]

Hi Jake, welcome to the forum.  What year or model is your 320?  It will help in fault finding.

Do you have a scanner for the car?  Knowing if there are any trouble codes helps.

Some BMW's need to have the battery registered to the car so the charging is right.  It will not stop the starting of the car.

Some older BMW's will loose the link (ISN number) between the DME (engine computer) and EWS (security system) when the battery plays up.

So, knowing the model/year of your car helps lots.