Strange Charging Issue

[leeandstaz]

2005 2.0 MK5 GT TDI 140.
Having a strange charging issue with it.
From a fully charged battery, Will last 4-5 days then end up stuck somewhere with a flat battery.
Get a jump start, 300 yards down the road and turn it off and it will start straight back up again.
It will then charge and start for a few days then go back to a flat battery again.
I have just today fitted another alternator as the one on it was a bit ropey and the problem still the same.
I am looking to get a new battery on Monday. But before I do can anyone shed some light on what else maybe the issue or if you have experienced similar?

 Thanks in advance.

[th3_f15t]

Do you leave it sat without being run when it looses charge? You could have an issue where the stereo is draining the battery which is a common issue if it's been upgraded from a lower spec unit in older cars (i.e pre-2007 produced cars). That issue can be solved by updating the CAN gateway to stop battery draining issues.

[leeandstaz]

No. you can turn it off and go to start it again within seconds and it just clicks as it does when the battery is flat.
get a jump start leave it a few minutes turn it off and it will start again. Drive 30-50 miles lets say and turn it off and theres a good chance it wont start again!
It just seems hit and miss if it will start or not.

[doylebros]

It's most likely a defective battery but once the vehicle is hot because it's a diesel the starter is required to spin between 2800 & 3200 rpm to start, so may be that's coming into play and the battery or starter is not meeting that starting criteria?

 Also don't discredit the previous poster can gate drain is a common problem for for many reasons but let's see how your new battery performs

[leeandstaz]

It's most likely a defective battery but once the vehicle is hot because it's a diesel the starter is required to spin between 2800 & 3200 rpm to start, so may be that's coming into play and the battery or starter is not meeting that starting criteria?

 Also don't discredit the previous poster can gate drain is a common problem for for many reasons but let's see how your new battery performs

 Thanks for the reply. It has only been doing it the last 3 weeks, Its the same battery as when we bought the car last February.
 I'm hoping that a new battery will finally cure this problem.

[dansmith180]

Maybe the colder weather has just killed off a battery that was already on its last legs, very common time of year for batteries to die.

[leeandstaz]

The new battery has cured the problem. What's more the ABS/TC light that was lit up on the dash has now gone out too and if fully functional again. 

[th3_f15t]

Happy days, cheers for reporting back. Info like this always helps for future cries for help.