My battery has no bad cells. Why the drain every time???
03-07-2016, 08:11 PM
#1
Three Wheelin'
Thread Starter
My battery has no bad cells. Why the drain every time???
I drive daily in my 997. Not the 25 miles or whatever it takes according to Porsche. New alternator, 2015 Interstate battery. Interstate says battery is good, no shorts or dead cells. According to my battery reader from Solar and my CTEK, this battery is always around 12.10-40v. Load test by Interstate says again that voltage is good. CTEK shows 1/4 battery this moment so of course I'm charging it.
I've posted previously about weird Durametric codes, likely voltage related. I've thought about buying the Walmart replacement battery.
Am I missing something here?
I've posted previously about weird Durametric codes, likely voltage related. I've thought about buying the Walmart replacement battery.
Am I missing something here?
Last edited by ALEV8; 03-07-2016 at 08:38 PM.
03-07-2016, 08:30 PM
#2
Racer
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I think it's the CTEK. Got tired of always having it say my battery was low when it wasn't. Stopped using it and use a 10amp real charger and no issues anymore. I don't DD so it's important for me to know. Even after fully charged and driven, CTEK says its low.
03-07-2016, 09:34 PM
#3
Three Wheelin'
Thread Starter
Well the battery reads too low, voltage is voltage. Reads way too low whenever I check it. I'll look into the ground strap.
03-07-2016, 10:58 PM
#4
Aside from taking constant readings on your voltage, is there any other signs of a weak battery? If you drive it daily, you shouldn't have to worry about hooking it up and constantly reading the charge level unless you're having starting issues, especially since you already verified the battery and alternator are good.
03-07-2016, 11:05 PM
#5
Rennlist Member
I can't tell which model you have, 997.1 or .2. The 997.1 models have a known problem with the alternator cable. Was the cable replaced along with the alternator? If not, maybe that is the problem? Search the forum for alternator cable threads and you will find a lot of info about it.
03-08-2016, 03:28 PM
#6
Three Wheelin'
Thread Starter
That's my next move. It's a 997.1 and the Durametric codes won't go away, hence my voltage investigation, and you gotta have solid voltage to smoothly operate. What I notice aside from that is a weird CLICK > key recognized > starter cranks over > car starts. Usually smoother starts/faster starts when battery has been freshly charged. Again, voltage is never over 12.4v. I was aware of the grounding cable issue. The car has a new frunk switch and passenger door regulator as well and Durametric isn't happy with either despite their replacements. Odd! I like to figure this stuff out myself. Go figure.
03-08-2016, 06:13 PM
#7
It may not be the battery. It could be a weak alternator, starter y-cable or parasitic drain, etc. You will need some electrical trouble shooting with a mulitmeter at least to diagnose it properly and accurately. I highly recommend this tester as a start for easy testing. It will tell you a lot. It has to be this one, not a look alike.
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03-09-2016, 06:17 PM
#8
Three Wheelin'
Thread Starter
SOLAR battery equipment way better...the BA7 model. Use Durametric for the alternator test....so I just checked my fully charged battery (first I've seen it at 12.6v ever) and starting system/cranking test reads 12.45v. Charging test reads 12.61v. Engine running 12.63v.
Last edited by ALEV8; 03-09-2016 at 07:12 PM.
03-09-2016, 07:08 PM
#9
You're missing my point of that tester. That tester is unique because it plugs in the cigarette lighter and can be left plugged in overnight w/o draining your battery. You can then see the battery voltage in the morning through the window BEFORE you unlock the car. That will give you a very accurate state of charge info of the battery in the morning and that tells you if you have a parasitic drain.
Once you unlock the car, a lot of electronics will be up and that lowers the battery reading.
Of course the more proper and direct way is to use an amp clamp to measure the drain directly on the battery cable but that takes more skills.
Once you unlock the car, a lot of electronics will be up and that lowers the battery reading.
Of course the more proper and direct way is to use an amp clamp to measure the drain directly on the battery cable but that takes more skills.
03-09-2016, 08:36 PM
#10
Three Wheelin'
Thread Starter
Alternator is new.
03-09-2016, 08:40 PM
#11
But what is the voltage at the battery or at the cigarette lighter when the car is running? It needs to be 13.5v or higher at all times whenever the engine is running.
BTW, new alternator means nothing especially the reman'ed ones. Most of them are no good, even from Bosch.
BTW, new alternator means nothing especially the reman'ed ones. Most of them are no good, even from Bosch.
03-10-2016, 12:22 AM
#12
Three Wheelin'
Thread Starter
RUF serviced my car exclusively prior to purchase. I'd think they use quality parts. Lemme check, brb.
03-10-2016, 12:26 AM
#13
Three Wheelin'
Thread Starter
Voltage to DME is 13.56v per Durametric.
03-10-2016, 12:36 AM
#15
This needs to be true when driving e.g., with a/c on, headlight on, etc. if you have that cigarette battery tester you can monitor the voltage when driving in real-time. Sometimes the alternator will crap out intermittently (e.g., when warmed or after a few miles of driving) or the y-cable resistance goes up after warmed up.
If the voltage stays above 13.5v at all times when driving like you would normally, then there is no reason why the battery is not charged properly given the miles you put per day. Of course unless the battery is faulty.
If the voltage stays above 13.5v at all times when driving like you would normally, then there is no reason why the battery is not charged properly given the miles you put per day. Of course unless the battery is faulty.