Battery dead - charging system problems again

Ugh this is becoming a recurring theme on my car. I've had the car checked out from the simple Autozone electric test, to me using a multimeter to check vitals, and then finally bringing it to the dealer to perform diagnostics. Each time nothing comes up! My problem is that after about 2-3 days of not driving the car the battery dies. This is very strange considering now when I do drive the car I commute about 25 miles each way. So it's getting plenty of opportunity to charge the battery. The voltmeter shows around 14 upon startup but once warmed up in the 13 range. Plus my multimeter also shows an acceptable range as well. Earlier last week I noticed something starting to go wrong when the car's accessories would flicker when I turned the key. It would still start but I had seen those symptoms before and knew what was coming. I used it last on Friday for a quick run down the street. When I went to turn it on last night then nothing. So in 48 hours the battery was dead. I don't have any parasitic drain as I checked for that and also no aftermarket accessories that could be killing the battery. There is no way that nothing is wrong with this car when we also have a Cayenne with 100s of electric bells and whistles and it's only used for short trips, sits for a couple of days at a time, and doesn't have these same issues. Any ideas? I know I haven't changed that alternator wire everyone talks about but would that show up as an issue in all of this testing? Both alternator and battery are only a few months old. Help!

I'd charge up the battery with a trickle charger and then see what happens. Even "new" batteries aren't always fully charged as they can sit for months before being sold. Would also recommend an AGM battery if you're not already. Frunk light staying on perhaps?

Voltage regulator on the alternator needs to be replaced. http://www.pelicanparts.com/catalog/..._pg1.htm#item2 About a 2 hour job, taking your time.

"Both alternator and battery are only a few months old." Either the battery is not holding a charge, the alternator is not putting out the voltage to recharge the battery, or you have some sort of parasitic draw when the car is off/parked. What brand/type of battery? I agree with a trickle charger but that doesn't solve the real problem. You need to have the battery load tested, and you need to check the amp draw from the battery when the car is off. Put your cell phone on video mode and put it in the frunk to make sure the light is going off. Also, when you are not going to use the car for a few days, you could disconnect the negative lead on the battery and then when you are going to drive, reconnect and see if you have power to start. Don't close the trunk lid completely if you do this! Make sure your battery terminals are clean and well connected. Check the 12V terminal in the engine bay for any sign of corrosion. And the engine ground as well. But more than likely it is going to come back to either the battery or the alternator.

First, get this tester (don't get anyyhing else). Leave it plugged in and observe it for a few days. https://www.amazon.com/gp/aw/d/B000EVWDU0/ref=mp_s_a_1_1?qid=1466435897&sr=8-1&pi=SY200_QL40&keywords=innova+battery+tester&dpPl=1&dpID=4105fQmT1vL&r ef=plSrch There are many tests that can be performed by a multimeter and dc amp clamp but this tester is so easy to use and can point you in the right direction before more involved tests. Your symptom is consistent with regulator and/or the starter cable. I've written direct test steps to pinpoint the culprit(s) on here and Renntech. Let me know if you can't find those.

One simple test point is once the car has warmed up, turn on your low beam and a/c. Your should have at least 13.5v. In fact, your voltage should be between 13.5v to 14.5v at all times when the engine is running, with or without load. Do you use an underdrive pulley by any chance?

You have a number of mods listed - are you running an underdrive pulley by any chance?

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That's what I did last night so I was able to start it this morning. It's about 6 months old at this point so it's not really "new" to the point where it wouldn't be fully charged now. It's an Autocraft battery with 80 amp hours and 1000 amps cranking. Not sure if that's ideal or not. Frunk light isn't on as I thought that might have been the case and took a video with my phone while closing it. Light goes off. Also looked into the courtesy lights but they also turn off after a few minutes. Wouldn't a new alternator also include a new regulator? Also wouldn't the voltage show some unusual values at the battery if the regulator was faulty? I'll change it out if it helps of course but I thought the new alternator would have included that. I listed the brand above but that battery replaced a previous one that was only a year old because of the same symptoms. So the battery didn't make a difference and neither did the new alternator. To me it does feel like a parasitic draw issue because when I run the car every day I don't have an issue. But even if I let it sit 2 days you can see the battery weakening. No corrosion anywhere on terminals or the jump terminal in the trunk. How do I check to see if the engine ground is in working order? Just ordered it and it'll be here tomorrow. I'll let it run overnight and see what it finds once I get it! No pulley but I'll run that test shortly and report back the results. Not to my knowledge or at least it's not something I installed. How would I verify? I know I just used standard sized belts on the car so not sure if that would be affected by an underdrive pulley. Thanks everyone!

"To me it does feel like a parasitic draw issue because when I run the car every day I don't have an issue. But even if I let it sit 2 days you can see the battery weakening. " That sounds exactly like parasitic draw. Of course it can also be weak charging that doesn't charge the battery fully, that's why you need that innova tester. Once you get the innova tester, please follow my post #34 here in your old thread: https://rennlist.com/forums/996-foru...l#post12614785

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Will do! Should have it this time tomorrow and I'll let it diagnose overnight and see where we go from there. Thanks again!

Do you lock the car? My battery was pretty old and I never had any problems with it, but whenever I left it at a shop for service they would call me to tell me that the battery was dead. I surmise that they didn't lock the car, which I heard actually puts more draw on the battery. I could leave my car locked for a week or more and not have any problems.

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Yes, if you arm the car and leave it undisturbed for a few days, the alarm will turn off the remote key fob monitoring and go to deep sleep to conserve power. If you don't arm it, the alarm has to listen to the remote key fob in case you use the remote. So that circuit cannot go to sleep. Anyway, even w/o arming, the car battery should still last at least a few weeks w/o problems. Our alarm draws tens of mA at worst and a heavy battery should have tens of Ah in it.

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Car sits in the garage so unlocked the whole time. Back when I was originally reporting the problem I did try to lock it but would rather not because it's much more difficult to jump the car when it's locked And again I compare it to any other car out there. Never heard of a dead battery after such a short period of time. I was going to test today with a multi-meter but I'll wait until I get that little device to record everything. Ok well off to plug in the trickle charger before going to bed...

If it's parasitic drain, you want this dc amp clamp to diagnose it quickly and accurately (as opposed to puttng a multimeter in series, which is tricky to do w/o interrupting the power therefore rebooting all the modules). Let's see what the innova tester says first. https://www.amazon.com/Uni-T-UT210E-...+current+clamp

Here is a link to help you.It is tedious but effective.You need a meter that measures milli-amps very accurately and it needs to be connected for many hours with all doors/hoods/windows closed and observed regularly The Trainer #27: 3 Ways Of Finding The Cause Of Key-Off Battery Drain (Parasitic Draw) - YouTube If you suspect the ignition switch is causing the drain(& you should!) ,just remove it to check if that stops the parasitic draw. Just remove the switch portion,not the entire lock.

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Ok things got really strange this morning. Not sure if it is related or not but I charged the battery overnight and headed off to work. About five miles into the drive I'm at a stoplight and the car just dies. Had no idea what happened but I thought the worst and put my hazards on and got myself prepared for what could be a long morning. Then I turned the car off, turned it back on and after a couple of turns of the engine it starts right back up without a problem. Didn't feel comfortable driving the additional 15 miles so headed back home and took the backup car to work. It seemed to be running fine but I did notice it was idling at about 1000 instead of the usual 700-800 RPM. Any connection to the electrical issues or another problem to look into? Thanks. I'll run the Innova test tonight and hopefully come back with something that points me in the right direction. I did something similar to that before with my multimeter and didn't find anything draining the battery. What I didn't do though is go back and check after a period of time. I would just check after the time period where the lights go off in the interior. So this is probably worth investigating as well. Thanks for the video!

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Just make sure you disconnect the trickle charger and arm the car tonight with the tester plugged in the cig lighter. Tomorrow morning just walk up and check the reading BEFORE you disarm the car. To check for parasitic drain, you need to wait for 1hr for the electronics to go to sleep.

I'm really leaning towards a defective ignition switch, and I hope that is all that it is. Do what Ahsai has advised and let's see how it turns out. BTW - my car has never just shut off like that. It points to something that would kill the ignition, like the ignition switch (electrical part).

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The OEM crank pulley looks like this: Standard pulley next to underdrive pulley: There are several varieties of underdrive pulley - some of them are anodized various colors; some have lots of material cut out to make the part lighter. If you don't see the factory part, you may have an underdrive pulley, and this could be contributing to your charging issues...

Re the engine shut down issue, you may want to scan for pending error codes and do an e-gas recalibration.

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Car is sitting now disconnected from everything and locked. Here are the readings I have taken so far today: 13.5 idle with lights and AC on 13.8 idle with lights and AC off 12.25 when I first lock the doors 12.19 after 15 minutes being locked 12.23 after 1 hour 15 minutes being locked Obviously my battery is low but is that because of the charging system? Doesn't appear to be as the voltage seems on target. Could I really have gone through two bad batteries in a row? I'll look at the reading before bed tonight and see what it looks like in the morning as well. You know that makes sense. I did switch out the ignition module years ago when I first got the car so it's going on about 6-7 years now and since it's a daily driver that switch gets used a lot. How to test an ignition switch? I switched it out before because the key was hard to twist and also I was having strange electric issues (like now!). Nope I have the standard pulleys. Thanks for the pictures for reference though! Didn't pull error codes yet and I won't until morning as I want to leave the car in its current state. I didn't see any CEL though when it happened. Also the high idle I reported earlier is gone now too and the car is running smoothly again.

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Agree the charging voltage looks good. The reading in bold can only mean one of the two things: - weak battery - large parasitic current draw that starts (or continues) as soon as the car stops Normally when you stop the car and lock the door after a reasonable long drive (say 20 min as least), the tester should read about 12.6v+ and it will stay around the same in the morning. It's ambient temperature dependent but I assume it's not extreme weather where you are. At this rate, your battery may drop to 12v in the morning. When you crank the car tomorrow, keep an eye on the tester and try to see what's the lowest momentary reading you have when you crank. If it drops under 9v, that also means your battery is not fully charged or it's weak. Note a fully charged battery open circuit (no load) should be around 12.7v. If it's 12v, it's only ~50% charged http://modernsurvivalblog.com/altern...-charge-chart/

I suggest the following steps: - Take the battery to an auto parts store for load testing - Take the car for a long drive (>30min) tomorrow then repeat the above tests tomorrow night and the next morning and make sure you see the same pattern - Get the dc current amp and do the parasitic draw tests. Leave the driver door, the frunk and the engine lid open. Use a screwdriver to "trip" all those latches to trick the car into thinking everything is locked. Then arm the car and don't get inside it (otherwise you will trip the motion sensor). Zero the amp clamp and hook it onto one of the battery cables. You should read < 1A for the first 20 min. After 1hr, zero the meter and read it again and you should see tens of mA. Will continue if you ever get here... Edit: ok, i missed this in your first post "Earlier last week I noticed something starting to go wrong when the car's accessories would flicker when I turned the key. ". Perhaps getting the ignition switch replaced too like what Joe suggested.

So I have results from the voltage test. Here is a compiled view of what I've observed: 13.5 idle with lights and AC on 13.8 idle with lights and AC off 12.25 when I first lock the doors 12.19 after 15 minutes being locked 12.23 after 1 hour 15 minutes being locked 12.19 after 10 hours locked So there is a draw but it's not that significant. It seems to me the biggest problem now is that the isn't fully charging. Keep in mind I had it on the charger the night before at 2 amps charge rate. And I charged it the night before. So why would it had started off at 12.25 when it should have been pretty charged up after only going 10 miles on a full charge? As for the flickering, it wasn't exactly a complete "on and off" process but more so a significant dimming of the instrument panel, radio, and AC console because all of the battery power is being used on the starter. I'm almost thinking right now it might be pointing towards the battery. But I don't mind replacing both switch and battery at this point if it will address this issue. I'll go for a drive a little later on and see what it does to the voltage on the car.

A long shot here, since I'm assuming you've disconnected/reconnected the battery a few times. Several times with climate changes (going from dry weather to long rainy periods, or from winter to spring, etc) the "space" between the battery post and cable can actually develop a very fine film of corrosion, and will provide the same indication's you're having. Looks perfect, but just enough resistance to prevent the battery from receiving a good charge. If you haven't done this already, remove BOTH battery cables and really clean 'em up.

I agree, since the voltage drop overnight was not significant. It seems like that the battery is not charging. Carl has a good point. Can you check this? When engine is running, measure the voltage of the battery with the multimeter probes touching the ceneters of the battery posts. It should be similar to what the innova tester says. If it's much lower, the problem is in the cables/battery connections. If it's as high as the innova says and yet the battery goes down to 12.2v right after engine shuts off, that points to the battery. Basically you want to check if the battery (battery posts) indeed sees that 13.8v from the alternator.

You may also want to make sure nuts #6 and #12 are tight and there's no corrosion. http://www.autoatlanta.com/porsche-parts/hardparts.php?dir=996-99-05&section=902-05

Another easy way to check whether there's corrosion between cable and post is to wedge an awl or small screwdriver between cable and post and see if the innova voltage changes, since you're bridging the connection. If any difference, you have corrosion.

Even light corrosion/contamination with a non-conductive substance can be enough to drastically affect the car. My wife's Murano was having an intermittent start issue that SHOUTED battery - hit the starter, get click-click-click, hook up jumpers, car fires right up - but the battery tested OK. The terminals and clamps looked perfect, but the problem didn't go away until out of desperation I spent some time on the terminals and clamps with a file...and the intermittent start issue disappeared and has not returned.

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Simple,cheap, quick,effective test. Eliminates/identifies one potential problem. Usually this kind of problem requires a plodding ,logical sequence of tests and lots of lists and notes. Flailing from one suspect component to the other can be futile.Hence the video earlier on Parasitic Loss. If the issue is charging also, ask about cable corrosion points and specifically the "Y" connector. When battery connections cause problems they are usually devoid of dielectric grease. Cheap insurance?

Went for a long drive yesterday and had the Innova plugged in the whole time. The good news is that the meter on the dash matches what the Innova tells me. When I got home I saw the battery was still hovering around 12.1 mark even after running for 18 miles, restarting once, and then running another 18 miles back on about 50% highway. All done with only the AC on. This morning was on the 11.9 mark so I did the voltage test to the terminals of the battery with the car on and off. In both cases the reading matches the Innova. With the car off the battery was on 11.9 but when I turned the car on then the voltage jumped to 13.7 at the terminals. There isn't any corrosion on the cables or the terminals as I did a cleaning before switching the battery out in September 2015. I'll clean the terminals again and try some dielectric grease but if it doesn't check out then I'll be pointing fingers back at my battery again. As for the car dying, I have heard that a bad battery could cause that so while the car was on I disconnected the negative terminal. Nothing really happened so don't think I can blame that. And I also jiggled the key and again nothing. So not sure what happened there. Thank you all for the help in troubleshooting this problem, all of your feedback is very much appreciated!

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Agree with your assessment if the 13.7v was measured at the battery posts, and not the battery cable screw terminals. Not sure if you want to further invest on testers but I use this excellent battery tester. It will show you if the battery is good and how much it has degraded from new so it gives you plenty of early warning before you get stranded. It also does not require the battery to be fully charged like other regular load testers. https://www.amazon.com/BA5-100-1200-...+battery+tster

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Yes I made sure to touch the probes directly to the battery posts as I wanted the reading right from the battery. I forgot that my multimeter actually has some diagnostic functions built into it: http://www.boschdiagnostics.com/diy/...nal-multimeter I'm going to try the Cranking Voltage - Battery Load Test function on it and see what happens. I'll try charging it again tonight and if it doesn't hold again will purchase another battery yet again. Maybe I'll finally find a good one like the one I had for the first 6 years with my car.

Keep in mind a trickle charger only outputs ~1A to charge the battery so even overnight (~12hrs) will only top off 12Ah and that's not much compared with the capacity of the battery (75-80Ah). You may need to leave it on for 24hrs or more to fully charge your battery.

I'm sure you'll get numerous suggestions on battery. For myself, Sears DieHard AGM. Awesome battery. I figure the load on it is terrific since I daily drive, run AC all the time, fans blasting away, and probably start/run 5-6 times a day. Never a glitch or hiccup. Always and every time. Good luck...hope it is just the battery. I've had worse luck with starters than with batteries. The OE one lasted ~12 years and 106K miles, second (my mistake) was a Bosch reman (lasted about 1.5 years then blew the bendix), then third one brand new Bosch. Been working good for 3 years. Back to batteries....

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My charger is actually a standard charger that puts out 2/6A but it doesn't have an automatic shutoff. So for that reason I always use it in 2 amp mode because I'm worried about overcharging my battery. Let me try the 6A mode for a few hours and just keep an eye on it. My father owns an auto repair shop and his over-the-phone diagnosis has been battery the whole time. He also suggested Diehard and if I remember correctly that's what my car had when I purchased it. Guess I shouldn't have strayed from what was there to begin with.

I would also try changing the ignition switch, mine failed in two years and causes battery drain and inability to crank the car. I never had the car die on me while driving, but for the $20 - 30 it would cost to change it doesn't hurt to give it a shot. Ill be changing the entire ignition at some point to the new and improved one.

Just wanted to post an update... I charged the battery and let it sit overnight and came back to a battery with full power. Hooked it back up to the car and it began losing power almost immediately. So either parasitic drain or a battery that can't handle load and discharges as a result. Not sure yet but I'm still researching. Drove the car into work this morning and had it showing 12.5 when I started it. Once I got into the parking garage it showed 12.46 which I thought was unusual because the entire drive my alternator was at between 13.4 - 13.8. Fun times trying to diagnose all of this!

Almost identical scenario: http://www.stangnet.com/mustang-foru...teries.790441/ Well almost..flickering lights, stalled out, battery not holding a charge. Sometimes a battery is just toast. Once it gets cycled too many times it just doesn't work right. Agree that you might have some draw when the car is off, actually it will, but it is very minute. At least if you get a new battery, you've eliminated one thing.

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It's normal to get low 12v when connecting the battery or when you open the doors as the electronic modules are activated. The innova reading should be: - ~12.5v in the morning BEFORE you disarm and open the doors. - Low 12.1 to 12.3 once you opened the door - 9v or above during cranking - ~14v once engine is started - 13.5 to 14v during drive - 12.5 to 12.6v as soon as you turn off the engine - ~12.5v after you arm/lock the doors and drop matbe 0.1v overnight

I'm really starting to believe cars have feelings and seek vengence when jealous! Brought home a Cayenne Turbo a little over a month ago and I've been in awe with all of the power and gadgetry in it. It's a much different car though but I think my 996 got a little jealous with everyone paying attention to this new beast sitting next to it in the garage. Anyway was heading to the dealer to pick up some wipers for the CTT with my 996. I'd been focusing so much on the charging/battery issue that I had let the little incident where the car died on me a week ago slip from my mind. At the dealer I pick up my wipers and I go to start the car. It turns over but it won't "catch". I guess it's like having a heart attack while visiting a friend in the hospital because I walked over to the service department and handed over my keys. Wife picked me up in the Cayenne and we left the 996 there. The initial diagnosis is faulty camshaft position sensor. Once they get it running they'll also perform an electrical diagnostic and see if we can figure out the charging/battery issue once and for all. And hopefully when it's all done the 996 will learn to live in harmony with it's new garage-mate

Well, you made it Cayenne's parts runner...you were asking for it

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I had a VW GTi years ago that did the same thing to me. I was looking at a Porsche 968 and on the trip back from the dealer it died on me in the middle of a highway in Tampa! Never had an issue with that car until it knew I was considering selling it! When I get the car back I'll provide info on the hopeful resolution of all these problems.

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I'm curious to see what they find.

Car came back with the diagnosis of a bad alternator. So I ordered the alternator from Amazon that Ahsai mentioned a few months ago. I also ordered the alternator/starter ground cable that I know is problematic. Once it's installed I'll circle back and update this thread with my results.

Your symptoms are exactly what mine had and all it needed was a $75 voltage regulator.

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3rd post in.

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I know I'm banging my head against a wall here. But how can we tell whether the alternator or voltage regulator is the problem? Since they're so closely tied together that's why I just figured replace the whole thing and be done with it. Tired of troubleshooting and not being able to trust the car.

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If your alternator is bad, you should not experience this. Chances are it's just the regulator (if it's really the alternator/regulator) but you are right there's no easy way to tell.

Btw, did the dealer say how the alternator failed? Was it low voltage/current or it has a parasitic drain? If its diodes have failed, it can still provide enough charging voltage but it will drain the battery whenever the engine is not running.

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This is what the service advisor wrote: "Checked charging system, found alternator to be charging at 12.7 volts with all electrical loads turned on. Alternator weak, recommend replacing." I did notice this before where upon startup my car does have higher voltage readings but once warmed up they started dropping. But even at 12.7 I thought that would be sufficient to keep the battery alive since 12.6 is what a fully charged battery puts out anyway. New alternator comes in today but the ground strap not until Friday. Doesn't matter though as I won't have time this weekend to work on it. Maybe during the evenings next week I will though.

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Yes, you need at least 13.5v to charge the battery. I also mentioned it in post #6. From your previous posts, I didn't see any mentioning of 12.6v. You always have high 13v. Anyways, a new alternator and a starter cable should only help. You can keep using the innova tester. If the voltage drops to 12.7v, it will show you a red LED saying your charging system is weak and you can't miss it.

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I never saw readings that low on the Innova until the morning I was bringing my car to the shop. But it would show lower readings (still out of the red LED range though) when the engine warmed up, just not as low as 12.6. I'm hoping once this is done that there really aren't any other potential points of failure as at this point I've replaced all of the major electrical system components!

Wanted to close this thread out for archive purposes and let everyone know the alternator and ground cable were replaced and life has been good since! The alternator was showing good readings while in the garage but after driving around would drop voltage by quite a bit. This was creating problems with the battery keeping charged. Now with the new alternator my voltage stays just under 14 volts and the car starts quickly in the mornings. Did the work myself so I purchased an alternator from Amazon for just under $300 and I believe the ground cable set me back another $75 or so. It wasn't overly difficult to remove and replace but I did hit a few snags - including creating a short with the starter because of the placement of the ground cable! But all is well which is what ultimately counts. Glad I am able to enjoy the car again. Thank you everyone who contributed to helping troubleshoot within this thread!

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