Mk5 BKD alternator question

[epidemic]

Hey everyone!

My mk5 Golf had a flat battery the other day. I have a android head unit which connects to canbus and shows battery voltage. When my car is idling/driving the voltage seems to spend alot of time around 13.2-13.5. Sometimes I notice it around 14-14.5 but not as often as I would like. Is this normal?

Also for a TDI I was reading the preferred battery is a 72ah battery as Diesels need a bit more juice when cranking. My current battery is 50ah. Looks like the previous owner cheaper out on the battery as it also is a **** brand.

Any feedback regarding this would be greatly appreciated! Could it be battery for alternator regulator?

Thanks all!

[BirdManFJ]

For cranking you need to look at the CCA rating of the battery (Core cranking amps) ie Delivery rate. The AH rating is it's storage capacity.

[Lucas_R]

Sounds like the previous owner just put in a cheap battery and probably one suited for a petrol Golf and not a diesel (as you mentioned, diesels need a stronger battery - although this should really only be an issue when starting the car as I cant imagine a diesel would demand any more from a battery once running than an equivalent petrol vehicle).

These 2x batteries below are suitable for a Mk5 and have AH ratings much closer to what you are looking for.

Century Car Battery DIN65LHMF | Every Battery Pty Ltd

Varta-E44 | Every Battery Pty Ltd

[epidemic]

Ok cheers lads. My battery is 500cca, which is strong enough however there are occasions where the car sounds like it's struggling.
Also regarding alternator voltages sometimes it's at 13.10. Does anyone else have an issue with alternator charge voltage? Or is this just how VW alternators work?

[Righteousness]

Ok cheers lads. My battery is 500cca, which is strong enough however there are occasions where the car sounds like it's struggling.
Also regarding alternator voltages sometimes it's at 13.10. Does anyone else have an issue with alternator charge voltage? Or is this just how VW alternators work?

What do you mean struggling? Battery voltage struggling or start up struggle?