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lofi

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Posts posted by lofi

  2. Battery overcharging and going flat

    in 981

    Posted

    So, an update.

    I sat with the car whilst it went to sleep. every 20 secs or so there was the click of a relay from the frunk.  It sounded like the relay sound when the DRLs switch off after locking the car. Every time there was a voltage drop, and there was not enough time between them for the battery to recover. Pretty sure this, whatever it is, was making the battery flat.  I also remembered I had an issue where the frunk lamp didn't light even with the frunk open.  I thought the bulb had gone but I tried it in the rear and it was fine.  So I had a good old pop around the frunk latch, opening and closing it with a screwdriver, spraying contact cleaner etc.

    Shut the frunk, locked car, all noises ceased and the battery stayed fine over night.

    Have had a code reader on the car and once all the codes i suspect are related to the original battery dying have been cleared and the codes re-read all that remains is the following:

    000401 Current distributor, terminal 30 reset

    C13212 Communication with alarm siren (rear 2)

    Car has been fine since but still has these codes and there is no sound at all when trying to lock the car with the doors or frunk open.  My guess is the siren is broken (as seems quite common).  At the moment I am considering leaving well alone as it all seems to be working properly (including the charging voltage when driving, 15v for a bit then dropping to 13.7v which is as I remember it) or opening the siren and having a look.  The siren appears to need cutting open. 

  5. Battery overcharging and going flat

    in 981

    Posted

    thanks @Paul P I have watched that and I am drawn to the alternator regulator (but only because I am still of the incorrect view that the charge rate from the alternator is wrong).  I have tried it without the alarm siren fuse in and still have an issue - BUT - I dont think I have left the car long enough to go fully to sleep given that doc says 35mins

  10. Battery overcharging and going flat

    in 981

    Posted

    48 minutes ago, ATM said:

    I left my 981 for 2 months maybe over winter and just drove it today for the first time.  Battery was dead and showing 4v on my charger.  I charged it for 24 hours and out it in the car and the car started fine.  I will now see if it holds charge.  I have a booster pack on hand if it fails to start. 

     

    My car was showing 15.0v once I started it so that is as explained normal for these cars.

     

    Regarding the alternator.  I believe these modern cars have complicated electrical systems.  Not sure why I think this but thats my belief.  So these alternators do not charge constantly like older cars.  This is for emissions as an alternator constantly blasting out peak amps will cause a drag on the engine and increase emissions.  Not sure if that helps explain whats going on with your car.

    Thanks @ATM that is helpful because it likely explains the 15v I have been seeing, which I think means the alternator is a non-issue.  Subject to the battery not discharging itself over night (out of the car) proving its ok, I think I'll be back to chasing down current draw.  One thing that has peaked my attention is that the driver's side window one touch function will not work and will not relearn. I wonder if the door control module could have developed a fault.

  13. Battery overcharging and going flat

    in 981

    Posted

    3 minutes ago, Paul P said:

    I guess the new battery could be faulty but i would be trying to “level the field” on the variables.  
     

    when using the ctek it shouldn’t be direct to the battery.   It should be battery positive and chassis negative.  
     

    Ideally the car should have been told it had a new battery.  Otherwise it will continue to charge the new one like it was charging the old one.  It doesn’t appear to be a good vs bad thing.  Many appear to have no apparent ill effects of not coding the battery and it’s unknown how far the “smarts” go with charging but if you are chasing potential charging issues then eliminating the doubt seems sensible.  
     

    the test that @Nobbie suggests seems a solid way of eliminating the new battery as an issue.  
     

    after that then perhaps a longer test of drain is needed.  For earlier gen cars I think it’s upwards of an hour before the car goes into proper sleep and that’s with the door and boot latches tripped to make the car think it’s locked.  

    Thanks - that's all sensible. I do have the conditioner set up like that, battery positive and to the chassis negative.  I will get a coder and do the battery, I understand the iCarSoft POR V2.0 and V3.0 can do this. Seems just a sensible precaution. I'll also do the @Nobbie test.

    When I did the drain test I didn't wait that long, but it did have the latches tripped, with the exception of the frunk, which I couldn't work out how to do.  

  15. Battery overcharging and going flat

    in 981

    Posted · Edited by lofi

    2 minutes ago, Carmine said:

    Not familiar with that particular Ctek charger; does it have an AGM mode?

    it does not - it has 6v, 12v and frost, though I now see this is for AGM batteries.  Seems I've had it on the wrong setting for four years!

  16. Battery overcharging and going flat

    in 981

    Posted

    Just now, Carmine said:

    You say you tested the original battery and it tested OK - can you expand on how that was done?

    What charger/maintainer are you using?

    Was the car stored indoors or outside? If outside can you confirm the drains aren’t blocked and that the carpets are completely dry?

    It was tested at a well know specialist - I dont know what they did to be honest.

    It is a cTek Multi XS 3600 (quite old)

    Car is kept in the garage.  Drains are clear, regularly rodded with my trumpet cleaner, drain valves removed, carpets dry last time I checked (not recently).

  17. Battery overcharging and going flat

    in 981

    Posted

    1 minute ago, Paul P said:

    14.9 volts is within spec for an agm battery.   They have different charging characteristics and can take a higher charge especially in lower temps. They can go up to 15 and a bit.
     

    not being pedantic but when you say trickle charger do you mean a conditioner - they are different things and living on a trickle charger with a constant “input” won’t be good for the battery.  
     

    sounds  like the battery has simply died.  Ideally the car needs to be told it’s got a new one of you replace it.  It helps with the smart charging and the stop / start stuff.  

    Ok, maybe it isn't two different problems, but only one, and that 14.9/15v charging is ok (I just never remember seeing it that high). In terms of charger its a cTek conditioner thing. 

    Do you mean the new battery has also died, i.e. your thought is that the voltage drop is a fault with the battery?  Maybe - I'll try Nobbie's suggestion and disconnect it and see what happens.

  18. Battery overcharging and going flat

    in 981

    Posted

    14 minutes ago, Nobbie said:

    If you are measuring all the current the battery is using then it won’t be draining the battery with 150mA. Might be worth taking the battery out, charging it up on the bench, disconnect it and then see if it then self discharges over a couple of days. Maybe the new battery is faulty? At least useful to eliminate this possibility first before changing anything else out.

    That's a good elimination idea, thanks.  The battery arrived charged and was on 12.6v iirc, though I guess it could have been damaged in transit.

  19. Battery overcharging and going flat

    in 981

    Posted

    Hi All,

    this might be two separate problems, but here goes.

    Boxster 981 been on the trickle charger over the winter and haven't used it for about three months.  On a run out the other day I noticed that the incarnation voltage read out was sitting at 14.9v, which is way higher than I remember.  Stayed that way over two 40 minute drives. Battery was tested and deemed ok. So I thought I would leave the car off the trickle charger. Checked a couple of days later and car was completely dead, couldn't unlock it open frunk etc.  Anyway, got to the battery and it is at 4v.  So I replaced it.  Checked the next day and it was on 10v (ish, can't quite remember).  So disconnected battery and put it on trickle and got it back to 12.6v.

    Next stage I wired an amp meter in series and watched the amp draw as the car when to sleep. Amp draw dropped to about 0.15A, then at stage 2 sleep 0.09A. That is not enough in my view to flatten a battery.  I did start pulling fuses and with the horn siren fuse out the sleep draw goes down further to 0.02A, but as I said 0.09A is nothing so I cannot understand when the battery is draining.

    Which brings me back around to the alternator (which I suspect has a voltage regulator on it).  Is it possible this is all related?  Am I chasing two different issues? What is going on?

    Would welcome any advice before I start throwing a new alternator on and then potentially disappearing further down the the route of trying to find what could be a highly intermittent current draw (although the battery voltage drop off, plotted over 12 hours is a consistent downward line).

  23. 981 Xenon Headlight Upgrade

    in 981

    Posted

    this might be worth a new thread but I have been keeping an eye of eBay for a replacement headlight unit as the corner has broken off mine and it looks meh.  There are a range of part numbers.  for example, mine are 981.163.123.05 and marked up with the code Z HSW XEN LV.  Lots of the ones on Ebay have a different end two numbers and are marked as Z HSW AFS LV.  Anyone know the differences and the corresponding part numbers?  My car is an S.

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