Dead Battery

ddorrer

Veteran Member
Joined
May 19, 2010
Location
WVa
TDI
2015 GSW Tdi, 2012 JSW Tdi DSG (Sold w/80k miles), 2010 Sportwagen TDI 6spd (Traded)
2015 GSW TDI 112k miles

2nd morning in a row car battery was dead. Stored in garage. I put it on a charger all day on day 1 then used the car to go out for dinner. Day 2 dead again.

Took a meter reading at 12.42 volts. Not enough juice to turn the engine. Now I have several questions:

What is the lifespan of a OEM battery?
What should a standing voltage be?
What should a charging voltage be; assuming the alternator is good?

I took the battery with me today so after work I will let AutoZone scan it before replacement.
 

06bluebeetletdi

Veteran Member
Joined
Sep 30, 2012
Location
Middlesex, NC
TDI
'14 Passat TDI SEL and '13 Beetle TDI
I changed mine proactively at 4 years (passat, it’s in my dad’s heavy equipment combination and still going 2 years later, it occasionally gets charged on a battery charger) 4.5 years (beetle), it lasted another year in my brother’s gas jetta. The beetle’s battery was replaced 2 weeks ago under warranty at 2 years old.
 

Lightflyer1

Top Post Dawg
Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
Lifespan depends on many factors. Some of which are has it gone dead once or many times? This is a battery killer. Standing voltage should be about 13.5 volts and charging about 14 to 14.5 volts. At 12.5 it is dead. Some get only 3 to 5 years from them. Others many more. If you want them to last keep them maintained (if needed) and charged.
 

DivineChaos

Top Post Dawg
Joined
Jul 27, 2019
Location
Minnesota
TDI
mk6 jetta sportwagen tdi
Lifespan depends on many factors. Some of which are has it gone dead once or many times? This is a battery killer. Standing voltage should be about 13.5 volts and charging about 14 to 14.5 volts. At 12.5 it is dead. Some get only 3 to 5 years from them. Others many more. If you want them to last keep them maintained (if needed) and charged.
standing voltage of the oem led acid is that high? i was always reading 12.5 volts after the head charge bled off. mine charges at 13.7-14.2 volts.
 

jmodge

Top Post Dawg
Joined
Jun 18, 2015
Location
Greenville, MI
TDI
2001 alh Jetta, RC2 w/.205's 5speed daily summer commuter and 2000 alh Jetta 5spd swap, 2" lift, hitch, stage 3 TDtuning w/.216's winter cruiser, 1996 Tacoma ALh
Chart says anything reading 12.6v or more is fully charged
 

Jetta_Pilot

Top Post Dawg
Joined
Apr 14, 2005
Location
West Hill, Ont.
TDI
2015 Passat Highline TDI Candy White (SEL Premium) long gone 2002 Jetta TDI
Led acid batteries are not designed to be run down to dead. That's a battery killer!
OP done that three times, time to replace it!
Even Deep Cycle batteries should only be down to about 30%, any lower is bad for them too.
 

DivineChaos

Top Post Dawg
Joined
Jul 27, 2019
Location
Minnesota
TDI
mk6 jetta sportwagen tdi
Chart says anything reading 12.6v or more is fully charged
thats strange. after my glow plugs ran mine was at 12.2. (this is after sitting for 15 hrs at 20f) car still spun over fast. although i have a new starter. if only the serial ob the battery could be checked to figure out age of oem battery.
 

ddorrer

Veteran Member
Joined
May 19, 2010
Location
WVa
TDI
2015 GSW Tdi, 2012 JSW Tdi DSG (Sold w/80k miles), 2010 Sportwagen TDI 6spd (Traded)
Battery replaced

Well folks, even though my battery had a standing reading of 12.54 volts, I had a bad cell. It did have enough cold cranking amps to start.
 
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