Thread: Flat battery due to radio when car is locked?

Got the car back and it turns out both batteries were problematic.

The main battery initially tested ok but a 2nd test found it had a dead cell so got that replaced. Looks like it was the original battery so was over 4 years old and probably due anyway.

The 2nd battery had a leak and had to be replaced. It was 18 months old but not a real expensive one. Got it replaced with a yellow top optima so that should be more reliable. The 2nd battery was well down on charge which I suspect was because it was working hard to try and charge the main battery. I'm sure the SC80 controller was working properly. Without the 2nd battery I'm sure I would have have starting problems earlier.

When MLR first tested the primary they couldn't find a problem with it. They found the 2nd battery to be faulty so I'm guessing they assumed it was drawing from the primary and had discharged it as this was the only fault found. I questioned this at the time as I thought that couldn't happen with the SC80. More investigation by MLR and finding the primary was faulty now makes sense.

Now, why did the initially primary drop charge?

I'm certain it went low due to the CD player coming on when the car was locked and should be sleeping. As I observed that when initially troubleshooting. Cant prove this happened originally though so interested if anyone knows of this happening on other D3's or 4's.
It also may have just died on its own.

Why did the CD player come on when the key was out of the ignition and locked?

Not sure this will be able to be determined. Nothing showed up in the fault code check. Could well be the car electrics detecting a low voltage and playing up so a bit of chicken and the egg maybe

anyways, car running again. Not cheap getting 2 batteries done same day but these things happen.

With Ashes beast there was a hidden find.

On the initial test the main battery was fine, 12.75V @ 595A & recorded a Good Battery & Will require Re-charge. Load tested via LR unit.

I spoke with Ash & explained that the 2nd battery was dead & leaking inside the Brake booster compartment & required replacement very quick indeed.
I said that we would do some more testing & charge the original battery & re-check. We checked all the codes in the vehicle & there were many comms faults which is what i initially thought there would be.

Initially i said that the 2nd battery could be draining the original, & thought that it was.
But i know Drivesafe's system & thought there has to be somethong else.

Bingo..

Dead cell in the Original battery, you could tap the battery, fine, then tap again & get a dead cell..So initial thoughts of a dead battery were correct & we had both batteries trying to run/start the vehicle & trying to keep the vehicle communicating with a varying voltage so to speak.

All fault codes were cleared & the vehicle went on its way.

Expensive, yes, but at least now you know you have a descent set of batteries in the vehicle with a damn good dual battery system that is doing its job properly.

Cheers

The 2nd battery was the cheaper AMP-TECH D48. Didn't realise it was leaking as bad as it was. Thought it just had a bit of build up on the terminal but obvioulsy more than that.

The Yellow top Optima looks like a much more robust unit so maybe anyone with the AMP-TECH should have a good look too see that it is not leaking.

Originally Posted by Ashes

The 2nd battery was the cheaper AMP-TECH D48. Didn't realise it was leaking as bad as it was. Thought it just had a bit of build up on the terminal but obvioulsy more than that.

The Yellow top Optima looks like a much more robust unit so maybe anyone with the AMP-TECH should have a good look too see that it is not leaking.

According to my battery guru Amp-Tech were recently taken over and quality is right down. He won't stock them any more.

This problem of testing a battery and not getting the correct info, the battery showing it is OK when it is not, is something I have come across a number of times this year.

It seems standard load testing of Calcium/Calcium batteries is not suitable for determining if the battery is on it’s last legs.

Not sure if this is a know problem or just a coincidence.

Mental note from now on-Kick battery to see if plates move!

A few times!!

What's the "expected" life of a battery ? - they are a component we tend to take for granted nowadays....but such a vital piece of equipment in the D3 - should I bin it after 5 years and start with a new one ?????
Interested in your comments/suggestions.
thanks

Hi oldsalt, I have never seen a reason for discarding a battery because it has reached a given age.

You can have the most expensive battery available and not get more than a few months out of it for a whole host of reasons and on the other hand, you could buy the cheapest Asian battery on the market and get an extra ordinary life span from it.

You just never know when a battery is going to die so my policy has always been, there is no reason to replace a battery until it needs replacing cause it has died.