Battery Issue

[Operandi]

I’ll try to keep this short and concise as possible but this is kind of a weird one, at least to me.

I recently picked up a 04 VW GTI. Overall the car has been great so far aside from 2 engine codes that came on after ~100 miles after bring it home, and the real issue; a recurring problem with the battery I’m having.

I commute to work, and if I leave the car sit for more than 3 days the car won’t start. Such as the case today when I was gona throw the bike in the back and go mountain biking. Normally I leave it charge overnight but I just went back and checked it after about 15 mins and the charger showed it nearly 100% so I decided to try it and it started. Not really great but it did start and seemed normal, I wouldn’t have expected it to start at all as it was just on 2amp slow charge.

Now the dealer is going to take a look at the engine codes for me and take care of that, and they can probably help with this issue too but I made a bit of drive to get the car (100 miles) and I’d just like to have some kind of understanding of what is going on if possible before I drive back to the dealer.

To me it doesn’t seem like 15 mins should be enough to really do anything. Does this seem odd to anyone else?

 

[Charles Kozierok]

Start by getting the battery stress-tested. The dealer should be able to do that.

 

[Zenmervolt]

If the car's an '04 and that's the original battery, it's just time to get a new battery.

ZV

 

[Operandi]

I just came back from having it tested at local friendly shop (no charge) and the load tester showed it as being good. And after driving around for a few bit (a few stops) the battery seems fine, this is all after being completely dead a few hours ago.

I don't think its the original battery as it looks pretty clean, but they didn't mark the date so I'm not exactly sure.

 

[The Stigenator]

i'll go with a bad battery / alternator.

check for energy leaks.

 

[Zenmervolt]

Do you have a multi-meter? If so, find out what the parasitic draw on the battery is. With the ignition OFF, remove the battery's ground strap, set the multi-meter to measure DC amperage, and then place it in-line with the ground strap and the battery's ground terminal. Then let us know what the amp draw is. It should be less than 100 milliamps (0.100 amps) if you've just had the car "on" and under 50 milliamps (0.050 amps) once the car has been "asleep" for a while.

ZV

 

[SpatiallyAware]

I just came back from having it tested at local friendly shop (no charge) and the load tester showed it as being good. And after driving around for a few bit (a few stops) the battery seems fine, this is all after being completely dead a few hours ago.

I don't think its the original battery as it looks pretty clean, but they didn't mark the date so I'm not exactly sure.

If the date isn't marked then it's probably the original battery.

FWIW.. I have not had good luck with those battery or alternator testing stations you see at advance/autozone/etc being accurate.

 

[JCH13]

Sounds like you have a current leak somewhere when the car is off. The battery is probably damaged from being completely discharged so many times too... it wouldn't be a bad idea to get a new battery in the near future.

Take a multimeter to your fuse panel and try to figure out what circuit is drawing current when the battery is out. I like to pull the fuse of the circuit in question, put the multimeter in current mode, and touch each fuse terminal to see if any current is being discharged.

A decent short-term stop-gap measure would be to pull the negative battery lead when you plan on parking it for a while. This will reset all you radio and clock, but it will keep your battery alive.

 

[XZeroII]

I'm pretty sure that some rogue clowns have stolen your spark plugs. Some diet Coke and a fire extinguisher should have you fixed up in no time.

 

[wirednuts]

if the battery is 04 then its probably just bad. cheap lead acids last about 5 years or so...

 

[marvdmartian]

If the battery is a maintenance free style, it could have a problem cell that's causing your difficulties. Unfortunately, lots of car manufacturers still use them for OEM batteries.

Other than that, my guess would be an unexpected load on the battery, while the car's off (someone tried their hand at electrical work, in the past, and now something that was a load while the engine was running is now a constant load), a dead short somewhere, or a problem with the line running from the alternator back to the battery (I had a fusible link go bad one time, that caused a similar problem).

 

[Operandi]

Do you have a multi-meter? If so, find out what the parasitic draw on the battery is. With the ignition OFF, remove the battery's ground strap, set the multi-meter to measure DC amperage, and then place it in-line with the ground strap and the battery's ground terminal. Then let us know what the amp draw is. It should be less than 100 milliamps (0.100 amps) if you've just had the car "on" and under 50 milliamps (0.050 amps) once the car has been "asleep" for a while.

ZV

I do but I couldn't find where the grounding strap ended so I wasn't able to remove it without just removing the ground, or at least I wasn't seeing how to do it.

 

[nitrous9200]

Take off the negative cable on the battery, then touch one lead of your multimeter to the metal part of the cable (that attaches to the battery post) and the other lead to the post on the battery...like this.

 

[Operandi]

Got it. I clearly didn't read Zenmervolt's post correctly.

 

[phucheneh]

Do you have a multi-meter? If so, find out what the parasitic draw on the battery is. With the ignition OFF, remove the battery's ground strap, set the multi-meter to measure DC amperage, and then place it in-line with the ground strap and the battery's ground terminal. Then let us know what the amp draw is. It should be less than 100 milliamps (0.100 amps) if you've just had the car "on" and under 50 milliamps (0.050 amps) once the car has been "asleep" for a while.

ZV

This. Except I have one meter lead clamped on the terminal, and one stuck into the post before I remove it.

This keeps a small amount of continuity between the battery and ground terminal as you remove it. If you just disconnect the ground terminal and then test, you may not get a good read, especially on later model cars. In addition to having to wait on the network to 'settle' upon reconnecting the battery, you also might kick off the draw when you disconnect, and not see it return until some other specific action causes it (this is usually related to a faulty electronic module (computer) of some sort).

A load test, or even just a conductance test (that simple little electronic box that says 'good' or 'bad') is usually enough to exonerate a battery.

Your battery is likely simply staying in a constant state of low charge, due to either a parasitic draw, a weak alternator, or bad cabling. Or, for great fun, some combination of those.

 

[Operandi]

I will keep that in mind. I’ll see if I can come up with some way to keep the leads connected while I disconnect the battery.

I’m fairly sure I can rule out the alternator, I’ve taken the car on few ~100 trips and have had no issues.