RogueM3

I had my (3) front radiators replaced at a reputable local shop last Friday and all seemed well with the car. When I picked it up I overheard someone ask the tech if the car had charged up okay and he said it had (sounded strange, but the car ran and started fine, so I didn't think anything of it).

When I went to start the car this morning it just "clicked" at me. I hooked it up to the Ctek and after 30 minutes it had 75% charge and started right up. I went to work and parked for 9 hours. When I came out it was dead again and would only "click". AAA ran a diagnostic and said from his test the battery was fine (needed to be recharged...hence not starting), though the starter and alternator checked out fine.

My question for you is that this issue has obviously cropped up immediately following my radiator replacement. Is there anything in particular up in the front of the car or removed during radiator replacement that would create a draw on the battery (enough to drain over a 9-10 hr period)?

I am taking the car back tomorrow, but am pretty upset about having to go back for an issue that was introduced during its last visit to the shop.

Thanks!

jpflip

May be the switch for the trunk. This switch operate both lights , engine compartment light and trunk light. Take a look if the engine compartment stays on through the opening on top of the engine cover.

RogueM3

I was hopeful...great suggestion. Didn't seem to stay on through the engine compartment.

I never really paid attention to the trunk light up front. Is that supposed to be on through the entire opening an closing of the trunk or only light when the trunk is fully open? My light seems to stay on until the trunk closes (and I cannot see anymore)..

wross996tt

The frunk light will stay on for some time (I think ~30 minutes) after both rear and front lids are closed. However if it stays on past that it will discharge the battery. Do you get any signals when you use your remote (indicating an open alarm).

RogueM3

Nope, just the standard 2 flash upon lock and 1 flash for unlock.

SSST

Batteries do wear out from time to time. Before you start a big electrical chase, have the battery tested. 90%+ chance you just need a new battery.

Second choice would be the alternator/belt. After that it gets more complex.

RogueM3

Forgot to mention the battery was replaced by Lamborghini Dallas before I bought the car. The PPI said it was weak, though I guess the dealer could have said they replaced it (when they didn't)...though they seem to be a reputable dealer. It is an Interstate battery (not OEM Porsche) but I cannot see that being a huge issue provided its the correct size, CCA, etc.

The test from AAA said the battery was good. I guess I can go run my tester across the ports and see what it says..but I imagine it will read fine.

Macster

Interstate batteries have come down in quality is my opinion. I had one go out in my Turbo after I bought the car then that battery died and was replaced last July and just last month the battery died again. All Interstate. The ones made in Spain are good I'm told but if they are made elsewhere...

Getting back to your car. What is the date code on the battery? If it was replaced the date code should be recent. If not...

Your car's battery checks out ok but odds are it loses power over time. This is how the 2nd battery in my Turbo was diagnosed as bad. Early in the AM when I first dropped the car off at the dealer the battery checked out just fine. But the tech waited until almost closing time and the battery had lost power. I forget how much but enough to warrant replacement. Afterwards the symptoms were gone, until as I touched upon above this battery failed.

The battery might not have been helped if the trunks were left open or the key left in the ignition, etc.

old nick

Brilliant thanks Wross911tt and all! Battery been discharging for a while now, and am getting occasional 'honks' when locking car. All makes sense now and can get a fix sorted. Cheers!

mmm951

The front bumper comes off when replacing the radiators and they might have messed with the switch by some chance in the process. If they struggled getting that black trim piece around the latch, then that might be a possibility. Or, your switch just happened to go out.

I had the same problem. Remove the bulbs from your engine and trunk compartment and see if the problem goes away. It is cheap and will let you know if it is the switch. My battery does not die anymore.

RogueM3

Evidently it boiled down to a dead cell in my battery (Interstate Battery dated 6/12 and only in use for past 4 months!). It was warrantied and replaced for free. If it happens again, I might well just switch to DieHard which I have always had good luck with.

It was strange as when I had dead cells in previous batteries the battery wouldn't take a charge nor start the car after charging and this battery would (but only up to 75% according to my Ctek).

Happy it wasn't more serious or the alternator, etc.

Kevin

I have recommended the Exide Edge AGM battery. It does not leak, with no cells to add water too. The nice thing about AGM's, is the ability to be charged at high amperage rates (and absorb all the amperage) when the battery is discharged.

Macster

May have to go this route. The new battery in the Turbo is showing signs of low voltage. Been getting low battery events from my in car wireless data logger/tracker and I checked the battery voltage yesterday and it was down to 12.1 volts.

The battery is not even 3 months old. If it does prove to be bad it is covered under warranty and I get a free replacement but gee, the battery installed in May 2012 died, then the replacement battery installed in Dec. 2012 gets replaced in Feb. 2013. I can't be running to the dealer every 6 months or less to get a defective battery replaced.

RogueM3

Same situation I may face down the line. If the first Interstate died in 3 months, what is to keep this replacement from doing the same and stranding me. A warranty/free battery is nice to save money, but there comes a time where the hassle of warrantying it is trumped by the quality of a new battery you have to pay out of pocket for...

Kevin

I have 3 customers including one of my own cars that had Interstate "short" term failures. Yes, the company stood up and replaced the batteries. But, within a short period of time they were failing again. Two customers put the Exide AGM in and all the problem went away. I am working with the Deka brand East Penn AGM battery. I am in the testing stage right now. But the Exide AGM is working very well.

My take is that for some reason the new batteries just cannot be discharged to a low voltage level. When the engine is started, the alternator cranks out a high amperage charge. I have noticed that the Interstates are venting to much fluid. The specific gravity in the cells is lowered and all over the place. This is not normal for new batteries.

Again, one of the main design features of AGM's batteries which are used as battery storage system for servers and solar systems, is the ability to take high amperage charge rates. The Exide AGM's are working without the mess of outgassing or "no start" conditions. The two customers have 4 months and 6 months use with zero issues.