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My 2015 4.0 just whooshed past 50k and the battery is now 5 1/2 years old. The car is garaged every night. It's had virtually no long-term exposure to sub-freezing temperatures. Boy do I love my car (whole different topic).
What is the life expectancy of the OEM battery? Should I be thinking of preemptively replacing it?
Are there telltale signs of demise that I should be watching for?
Mine’s done 8 years. I’m just getting it changed out now.
Signs it’s failing.
• Flashing glow plug light, but no glow plug fault.
• Slower starting, or continuous cranking and no firing. <8v as it’s cranking.
• Lots of random error codes.
• Stuff powering down
• Easier to flatten the battery, watching TV whilst parked etc.
You had any of these?
Last edited by Bladerunner; 03-12-2020 at 01:32 PM.
If it were me, I'd replace it. 5.5 years seems to be a really long time, as most of my batteries average around 4 years. Plus when the battery fails, it could leave you stranded or in a situation where "the best battery for your vehicle" won't be readily available.
Mine’s done 8 years. I’m just getting it changed out now.
Signs it’s failing.
• Flashing glow plug light, but no glow plug fault.
• Slower starting, or continuous cranking and no firing. <8v as it’s cranking.
• Lots of random error codes.
• Stuff powering down
• Easier to flatten the battery, watching TV whilst parked etc.
I work with batteries of differing types in various systems and the standard replacement cycle for deep cycle/VRLA/AGM batteries is 5 years.
Based on my experience testing and trending the different parameters it is usually not long after that where age really seems to take hold. Some obviously do better than others, even among the same brand/date code/batch, but when they start to really degrade it is usually pretty rapidly, and doesn't always do so gracefully. These batteries are usually kept in far more favorable conditions as ours, even if ours are actually in a lot better of an environment than most automotive batteries.
That being said, at the age of yours, I would think it prudent, and in your best interest to change it out sooner rather than later. It's not a case of if, but when, and I can almost guarantee that when it finally does give up the fight, it will be at the most inopportune time!
New battery with the BEM information A broken battery monitoring cable. Can’t code the battery now.
However despite not coding the car is starting well and all systems are working.
The battery monitoring connector is on order and will be reattached in a few days.
It’s been broken for a while.
Lots of real error codes had been generated as a result of this broken cable and spurious error codes as the car randomly shut equipment down, in a panic over the voltage available.
The old battery appeared to have a good charge but under cranking would drop to under 8v occasionally and wouldn’t fire.
You can’t really tell this by how fast it turns over. It’s a bit more subtle.
Audi main dealers didn’t find this fault. Even though the car said it couldn’t communicate.
AA spotted the battery monitoring comms issue. Didn’t spot the broken cable.
Few years of seeing Audi and other garages about the starting issues. Unnecessary part replaced. Starter relay. Old one binned.
Audi battery management extends the life of the battery. Moderate climate, well taken car of, regular use - over 10 years on my D2. 2004 I replaced in 2016 I think it was.
However despite not coding the car is starting well and all systems are working.
The battery monitoring connector is on order and will be reattached in a few days.
It’s been broken for a while.
Lots of real error codes had been generated as a result of this broken cable and spurious error codes as the car randomly shut equipment down, in a panic over the voltage available.
The old battery appeared to have a good charge but under cranking would drop to under 8v occasionally and wouldn’t fire.
You can’t really tell this by how fast it turns over. It’s a bit more subtle.
Audi main dealers didn’t find this fault. Even though the car said it couldn’t communicate.
AA spotted the battery monitoring comms issue. Didn’t spot the broken cable.
Few years of seeing Audi and other garages about the starting issues. Unnecessary part replaced. Starter relay. Old one binned.
Self diagnosed it in the end.
Hi Bladerunner; useful post thank you.
I'm in the UK too, I have a 2015 TDI 3.0; would you care to say where you sourced your battery from and how much, roughly, you paid for it?
And am I right in assuming you didn't / don't have a VCDS?
03-12-2020, 01:03 PM
OEM Battery Life Span?
