Mystery: Dead Radio, ... 2 week pass, dead battery?

Mystery: Dead Radio, ... 2 week pass, dead battery?

Clue #0 ? Performed the antenna mod, using thinly insulated wire a few months ago.

Clue #1: My radio stoped working. I kept driving for a few weeks with no problem.

Clue #2 The car always started without hesitation (not noticably slow). But I did occasionally get a stalled start, which I attribute to the 14lb flywheel.

Clue #3: Then I parked it for 10 days to re-adjust the 658 5th gear. No lights left on. Then I notice my 2 year old Optima Red Top 75/35 is toast and does not hold a charge. And I could not

even jump the car.

Clue #4: While trying to charge the old battery, I notice the Radio works again.


Lucky for me the battery warranty is 100% free replacement for the 1st 3 years!

So I put the new one in and as a precaution, I pulled the radio out.

I will be monitoring voltage daily with my scangauge 2, before and after starting the engine.


So my theory is there is a current leak somewhere (radio?) that drained the battery to 0%. It was starting to go dead before I parked it. After I parked it, it quickly died, and fried the battery. I am surprised SUCH A NEW, HIGH QUALITY battery can be toasted so fast.


$5 paypal to the 1st person to solve the mystery and save my new battery.

If leaving the radio out makes the problem go away, than I'd say the problem is the radio.

If tere were no problems prior to Installing the Optima, then perhaps your new battery is defective.

However, I don't think the radio is the culprut. (only a symptem). My guess would be a bad diode in the alternator or the alternator not charging.

After you rule out the battery, one thing you can do is make sure your battery is fully charged, (on a battery charger) and then have your alternator checked by a shop that is qualified to do automotive electrical repair and diagnosis. Also some auto parts stores will check alternators in the car for free and might give you a proper diagnosis for no cost.

Also make sure the alternator belt is not slipping.

If I'am right donate the $5 for me to the TDIClub............................

T.D.

I'm putting the radio back in and watch my voltage. If the radio goes brain dead again, its out for good.

The optima does not meet spec.

While I realize lots of people are using it, it has about half the required Ah for the car, I still don't understand why people would spend more on a battery that does not even meet spec for the car.

Odds are that the battery is dying from having more demand than it can supply, and powering the radio is just enough to make it drain.

Are you sure? I recall it having more capacity than the OEM battery I took out. Unfortunately I don't have the OEM number handy. I believe the Red top Optima was rated at 785 CCA.

Keep in mind the optima is a more modern design that could easily have more capacity and lighter weight.

Traditional batteries have a lot of extra lead which may not be adding capacity.

puter said:

The optima does not meet spec.

While I realize lots of people are using it, it has about half the required Ah for the car, I still don't understand why people would spend more on a battery that does not even meet spec for the car.

Odds are that the battery is dying from having more demand than it can supply, and powering the radio is just enough to make it drain.

Click to expand...

GdB said:

Are you sure? I recall it having more capacity than the OEM battery I took out. Unfortunately I don't have the OEM number handy. I believe the Red top Optima was rated at 785 CCA.

Keep in mind the optima is a more modern design that could easily have more capacity and lighter weight.

Traditional batteries have a lot of extra lead which may not be adding capacity.

Click to expand...

Cold cranking amps are not what you need to be looking at, you need to be looking at Amp Hours. The Ah rating for a red top is ~40Ah, the spec rating is 80Ah

The best battery you could buy would be an interstate MTP-H7. It's an excellent battery and is within spec.

There's a bunch of people on here that have been buying red tops and I really don't know why. They are not within spec, they cannot supply the power necessary over time for a tdi. I'm sure they'd be excellent for a gasser, but tdi's have a higher draw.

There is also a certian amount of parasitic drain associated with the alarm system. If the alarm system did not go into low power mode, then the car will pull about 0.25 amp.

10 days * 24 hours/day * 0.25amp = 60Ah and a dead battery.

puter said:

Cold cranking amps are not what you need to be looking at, you need to be looking at Amp Hours. The Ah rating for a red top is ~40Ah, the spec rating is 80Ah

The best battery you could buy would be an interstate MTP-H7. It's an excellent battery and is within spec.

There's a bunch of people on here that have been buying red tops and I really don't know why. They are not within spec, they cannot supply the power necessary over time for a tdi. I'm sure they'd be excellent for a gasser, but tdi's have a higher draw.

Click to expand...

A way under AH battery sure sounds like the problem. If the old battery still takes a full charge and the radio problem goes away, the under AH Optima is the problem. Of course the old battery, after sitting around for 2 years, might not have full capacity, any more.

Ya, the red tops do work great in a gasser. The best part about them is that they are sealed and don't corrode the battery tray.

In the 2006 Bentleys, one of the battery types for the TDI is called AGM (Absorbant Glass Mat) and it is sealed and maintenance free. It is not recomended for use it in a car that didn't come with it, though.

Could the AGM be constructed the same as an Optima? (Spiral Cell)

weedeater said:

There is also a certian amount of parasitic drain associated with the alarm system. If the alarm system did not go into low power mode, then the car will pull about 0.25 amp.

10 days * 24 hours/day * 0.25amp = 60Ah and a dead battery.

Click to expand...

Good info folks! Thanks!

What does gasser vs TDI starting amps have to do with? Nothing, the red top is within spec for CCA (cold cranking amps), 785.

The parasitic drain problem is only a function electronics equipement parasitic load.

So the red top weighs about 35 lbs less, but gives you about half the battery life when the vehicle is parked for an extended time.

Since I'm in sunny California, I'm going to buy a solar charger instead of carrying 35 lbs of extra battery. It will come in real handy for camping trips also. I think silicon will turn out to be a better investment than lead.

HMMM here are some:
http://www.batterystuff.com/solar-chargers/

AHA!
SUNLINQ 6.5 Watt Solar
$86.00
http://www.batterystuff.com/solar-chargers/PF6.5w.html


Even better but $$$$=OUCH!
Solatec LLC has introduced flexible, rooftop-mounted solar panels for hybrid vehicles...
http://www.solatecllc.com/
MSRP is $1,595 plus installation labor

GdB said:

Good info folks! Thanks!

What does gasser vs TDI starting amps have to do with? Nothing, the red top is within spec for CCA (cold cranking amps), 785.

The parasitic drain problem is only a function electronics equipement parasitic load.

So the red top weighs about 35 lbs less, but gives you about half the battery life when the vehicle is parked for an extended time.

Since I'm in sunny California, I'm going to buy a solar charger instead of carrying 35 lbs of extra battery. It will come in real handy for camping trips also. I think silicon will turn out to be a better investment than lead.

HMMM here are some:
http://www.batterystuff.com/solar-chargers/

AHA!
SUNLINQ 6.5 Watt Solar
$86.00
http://www.batterystuff.com/solar-chargers/PF6.5w.html


Even better but $$$$=OUCH!
Solatec LLC has introduced flexible, rooftop-mounted solar panels for hybrid vehicles...
http://www.solatecllc.com/
MSRP is $1,595 plus installation labor

Click to expand...

um, but the red top is still _not_ within spec for amp hours, and that DOES matter.

you have higher drain due to glow plugs, higher drain due to high compression start, add that to drain from sitting there running the alarm and running the other electronics and you have a significantly higher drain than with a gasser.

In addition to this, each time you start the car you will be draining the battery much more than it is designed for (it is not designed for that type of load...hence the lower Ah), this means the battery will have a shorter lifespan...and die sooner.

You solar charger may (and I stress the may) allow the battery to start your car without a problem despite the higher drain, but you will still have a shorter lifespan on the battery in the end.

I'm sorry, but the missconception that Amp Hours do not matter is just wrong.

puter said:

um, but the red top is still _not_ within spec for amp hours, and that DOES matter.

you have higher drain due to glow plugs, higher drain due to high compression start, add that to drain from sitting there running the alarm and running the other electronics and you have a significantly higher drain than with a gasser.

In addition to this, each time you start the car you will be draining the battery much more than it is designed for (it is not designed for that type of load...hence the lower Ah), this means the battery will have a shorter lifespan...and die sooner.

You solar charger may (and I stress the may) allow the battery to start your car without a problem despite the higher drain, but you will still have a shorter lifespan on the battery in the end.

I'm sorry, but the missconception that Amp Hours do not matter is just wrong.

Click to expand...

Your missing the point. A little electrical engineering is needed here.

1. Starting & glow plugs is driven by CCA, for which the red top is rated within spec, because it has a low enough resistance to deliver plenty enough amps. THIS IS BASICALLY THE ABILITY FOR THE BATTERY DELIVER ENOUGH POWER (WATTS=VxA = ENERGY PER UNIT TIME) TO START THE ENGINE. CCA is used because VOLTS=12 is standard for all car batteries.

My 2 year old red top was going strong until I let it drain down while parked.

2. Ah is really just a proxy for ENERGY (W x h) relating to slow discharge loads.

So lets do some calc's:

The glow plugs start at 140A and stabilize at 36A, so it takes a full hour to kill the battery with the glow plugs.

I'm not sure what the starter is rated at, but the cable to it is either 2 or 4 gage, which are limited to 135A and 180A. So with a 40Ah battery you could crank the engine for about 10 minutes at least, but the starter would melt down long before that.


So all you red toppers are 100% fine.

1) I have a degree in CE.
2) CCA is the number of amps it can deliver to crank the engine, over a short period of time.

You take the glow plugs, and then the engine crank, and it needs to deliver high current over a longer period of time. Add this to the fact that the car has been sitting out for a day running the alarm, ecu, etc. and you are draining the battery much lower than it is designed to be drained.

Red tops ARE NOT TO SPEC. can I make that any more clear? The spec is for 80 Ah, red tops deliver HALF THAT. How can it be any more clear that the red top is not to spec?

Do all the calculations you like, it will not change the fact that the red top is not to spec and is not designed to deliver the REQUIRED Ah.

Why don't you try getting a battery that is within spec and see if you still have the same problem? An Interstate MTP-H7 is well within spec and should work great for you.

puter said:

1) I have a degree in CE.
2) CCA is the number of amps it can deliver to crank the engine, over a short period of time.

You take the glow plugs, and then the engine crank, and it needs to deliver high current over a longer period of time. Add this to the fact that the car has been sitting out for a day running the alarm, ecu, etc. and you are draining the battery much lower than it is designed to be drained.

Red tops ARE NOT TO SPEC. can I make that any more clear? The spec is for 80 Ah, red tops deliver HALF THAT. How can it be any more clear that the red top is not to spec?

Do all the calculations you like, it will not change the fact that the red top is not to spec and is not designed to deliver the REQUIRED Ah.

Why don't you try getting a battery that is within spec and see if you still have the same problem? An Interstate MTP-H7 is well within spec and should work great for you.

Click to expand...

I respectfully disagree.

The battery died because of a malfunction causing a parasitic drain (radio malfunction).

An OEM would have died just the same, except it would take a few more days because of the extra Ah.

I have an degree in AE, ME, and an A&P and regularly utilize that engineering knowledge.

But hey go ahead and knock your self out and carry around 40lbs of extra battery which will only help you for SLOW parasitic load time to dicharge.

You could probably start a TDI with a 5lb 10Ah A123 lithium battery because they have very low resistance.

BTW Starting the engine will require less than 1 Ah (worst case) based on these conservative estimates:

Starter: 200A x 3.6sec/3600sec/hr = 0.2Ah
Glow plugs: 100A x 18sec/3600sec/hr = 0.5Ah
----------------------------------------------
Total starting needs less than 0.7Ah

So both 40Ah and 80Ah are way over the starting needs.

So it seems that CCA has everything to do with starting and Ah is not a factor unless your battery is dead and you get much closer to 1Ah.

Lets do a comparison. I have a scan guage 2 and after starting the battery voltage drops by about 0.2V before the alternator gets a chance to top it off.
What does your OEM do?

batteries are not designed to be deep-drained.

Every time you do that you lower the life of the battery.

The engineers at VW spec'd a battery at 80 Ah for a reason, they know a lot more about this car than you or I.

In the end, the battery does not meet spec, regardless of whether or not it CAN start the car. The fact is it is being drained further than it is designed for.

everything you have said is true, it's just not complete. You're only considering whether or not the car can start with the battery, not how many times, how deeply it is being drained, or if it is designed to be drained as far as it is. I'm not claiming that a red top does not have the cca to start the car, I am saying that its life expectancy will be lower than a battery that is designed to be used with a tdi.

If you want to buy more batteries more often because they die earlier to save some weight, then go for it. I personally would rather have a battery last 6 or 7 years than 3 or 4.

Survey!

I am sure my red top would last at least as long as an OEM 80Ah if it had not been deep drained due to a MALFUNCTION.

I chose the red top because I pump up the tires for better performance and MPG (see bold below).

I started a survey here:

http://forums.tdiclub.com/showthread.php?p=2125749#post2125749



Take a look at this (It's called progress in battery design):

http://www.dcbattery.com/optima_red.html

"Optima RED TOP Starting Batteries designed and engineered by Optima Battery. With Optima Batteries you will discover the revolutionary new technology by Optima Batteries which has changed the way the world looks at batteries:

Optima Batteries famous SPIRALCELL Technology was invented by Optima Batteries engineering staff. OPTIMA BATTERIES Red Top starting battery significantly outperforms and outlasts conventional flat plate batteries with a life span two to three times longer than the competition. Optima Batteries SPIRALCELL design uses high purity lead plates wound with a glass mat that absorbs electrolyte like a sponge. Optima Batteries generate extremely high power, very low internal resistance and other features that translate into the following benefits:

* Optima Batteries lasts two to three times longer than conventional batteries, providing years of reliable, convenient performance and exceptional value. Optima batteries high purity lead design provides a much longer shelf life, meaning Optima Batteries can sit unused for up to one year and still start your vehicle.

* Optima batteries are true "Zero Maintenance" - All Optima Batteries are completely sealed, absorbed electrolyte design means OPTIMA Batteries won't spill, leak, or corrode - it's the safest, cleanest battery on the market. You'll never need to clean terminals or add water, and OPTIMA Batteries can be mounted in any position - sideways, or even upside down.

* Optima Batteries deliver high power output both faster and longer than conventional batteries, resulting in greater cranking ability and less capacity reduction at high current loads. Optima Batteries low internal resistance enables the Optima Batteries to recharge twice as fast as other batteries.

* Optima Batteries are extremely resilient to heat and cold - tests prove that Optima Batteries performs better in all temperature extremes than conventional batteries. Optima Batteries are vibration resistance - the SPIRALCELL design of Optima Batteries provides unequaled vibration resistance for all your off-road, commercial, and heavy duty industrial needs. "

batteries are not designed to be deep-drained.

Click to expand...

That depends on the battery.

AGM batteries are wonderful things...

FWIW I've owned several Optima red-tops and even a couple of yellow-tops with a success rate of about 50/50. I've used these in garage queens and daily drivers.

Red-tops seem more delicate when it comes to how far the charge is allowed to go down, even more so than a conventional battery. I've even had a couple go bad after one year on a good auto trickle charger. One of my Yellow-tops wouldn't take a charge after only dropping to 1/2 capacity.

I was a big Optima fan-boy over the years, but no more. You can find plenty of similar stories on an Internet search.

Tweekster said:

FWIW I've owned several Optima red-tops and even a couple of yellow-tops with a success rate of about 50/50. I've used these in garage queens and daily drivers.

Red-tops seem more delicate when it comes to how far the charge is allowed to go down, even more so than a conventional battery. I've even had a couple go bad after one year on a good auto trickle charger. One of my Yellow-tops wouldn't take a charge after only dropping to 1/2 capacity.

I was a big Optima fan-boy over the years, but no more. You can find plenty of similar stories on an Internet search.

Click to expand...

I don't blame the battery for this, it's the miss application of the battery by putting it in a tdi, which is designed to have higher drain. Thank you for the case example of what I was saying.

The specifications are there for a reason, I don't see why people buy batteries out of spec and then try to find any reason other than the battery for why it died.

When you buy a battery, they often only mention the CCA spec, not Ah spec.

GdB said:

When you buy a battery, they often only mention the CCA spec, not Ah spec.

Click to expand...

That is true, which makes buying a battery for a tdi very hard.

Forum members have actually contacted the manufacturers to find out the Ah of their batteries to find out if they are within spec.

Not giving the information does not mean it is not important.

True, but it meets the TDI specific starting spec requirement (CCA).

The spec that it does not meet is not really TDI specific.

Sounds like some experience is contradicting Optima performance claims. Survey results should confirm or deny this.

Um, the spec calls for 80 Ah for the battery.

What spec are you referring to that does not have a min Ah?

Well I have not actually seen the spec, but the OEM battery has 2 performance ratings, CCA and Ah, So I assume the spec calls out:

a. Ah

b. CCA