dead battery symptoms?

[ald1717]

pretty sure my battery isnt holding its charge anymore at idle shows 14.7volts and rises with revs so alternator works, 3 times now the car has failed to start in the morning but after jumping and driving for bit it will start again, and same thing maybe a few weeks later does this sound right?   anyone else had battery go on these cars and if so what were your symptoms?
 thanks all

[rich83]

pretty sure my battery isnt holding its charge anymore at idle shows 14.7volts and rises with revs so alternator works, 3 times now the car has failed to start in the morning but after jumping and driving for bit it will start again, and same thing maybe a few weeks later does this sound right?   anyone else had battery go on these cars and if so what were your symptoms?
 thanks all

How old is it? Mines a 2007 and it's on its 3rd battery

[ald1717]

i have had a look for a datecode which is  but cant find anything obvious, its a nappa battery and it has a din-57412
etn- 574012064  and a code further down - kt9124  although i have no idea if any of these relate to date of manufacture..
also would a dead battery cause any other issues, like intermittent performance issues, if the alternator is having its power drained from the battery constantly needing charged whie running? or is the battery just for starting and then serves no purpose?

[JoshB]

The battery should have its Ah rating, or crank amp rating written on it somewhere. Then you need to borrow a battery tester and see how they compare.
A dead battery “shouldn’t” cause performance issues though.

Have you had a check round to make sure nothings getting left on? Interior light, sidelights, something in cig lighter socket, something in obd port…

[ald1717]

yeah i was thinking that about drivig issues, was using a febi pcv which i think is causing intermittent issues,put a forge delete on until i get a vw pcv, but pretty sure its the battery causing the no start as once its started the alternator charges it up its just not holding the charge, new battery time.

[titchy]

i had a similar problem new batt. took the fuse box cover off just below there are 4 or 5 brass connectors red and black green copper corrosion was causing the batt. to drain quick wire brush some vaseline fixed

[pudding]

Check you have the right battery in there. It should be an 096 size, around 75AH.  Some people fit smaller batteries as they're cheaper, but these cars need the right battery otherwise there's too much load on it from the EPS.

If the meter is showing ~14 volts when the engine is running, things aren't desperate yet.  Typical signs of a dying battery include very sluggish cranking speed, lengthy fire up times, slow windows, slow wipers, dim headlights etc etc.

Does your battery have a health indicator?  A lot of them now have a dim green light on the top when it's healthy, which turns white when it needs replacing.

[ald1717]

its the right battery, and ive had all the symptoms of it dim headlights, slow windows, very sluggish turn over, 

[pudding]

Why do you keep asking questions on here, and then when people respond, you're like yeah I know that already.  WTF???

[ald1717]

i asked what the symptoms of a poor battery on the mk5 gti were as this was my first battery change on this car...
you asked if it was the right size and i replied yes,

[ttelracs]

I just replaced mine as I noticed when I worked on the car and was listening to the car radio for about 30 mins it would turn over a bit too slowly for my liking and a couple of times if longer, it wouldn't turn over at all and would need a quick charge over night.  I picked one up on eBay with a 6 month warranty for £30. I;m too tight to buy new...

[xcentric]

its the right battery, and ive had all the symptoms of it dim headlights, slow windows, very sluggish turn over,

those are the symptoms of a dying battery.....

may be worth buying a battery tester  - I got one of these https://amzn.to/3wZhfZ2 which is helpful.

[ttelracs]

Mine wasn't as  bad as above and I still got rid.
I then sold the old one on stating it's issues and still got £15 back, so effectively paid about £20 for a battery in a much better condition.  Used the packaging the new one came in which also saved taking it to the local tip for recycling.