battery drain.. but no drain? doing my head in

deMort · 4 Jun 2018

Theres nothing wrong with the chargeing , the alternator should adapt for the higher electrical loads and thats what its doing .

14 volts is fine , 997 and 15 volts is fine .. its down to the charge state of the battery .

So far you seem to have nothing wrong .. dont have a miniture battery fitted do you ?

Ok .. what to suggest .. hmm ..

Foam base panel behind the rear seats , pull that out and youll have an ally panel held in place with 10 mm nuts .. either remove or peer under it .. your looking for a battery .. a long grey lead .. a purple wire , a black wire and another ally box .. that would be a tracker and the battery would be the problem.

Tracker batterys die and the unit trys to charge the battery with engine off which it shouldn,t .. you will get a pulsed discharge of about 1 amp every 30 - 60 seconds .

You havent seen this on your meter but im running out of idears here !

No umbrella against the seat switches .. if full electric seats then just make sure its all moveing on both sides .

i think another discharge check is in order to make sure nothing has been missed .. set it to 10 amps this time .

A meter with a record function is what i use when i get desperate .. i can leave it over night and read max/min so it will 100% prove there is no discharge .

All im left with is the battery is not holding charge for very long .. 4r days is too short a period for a battery to be low enough that it struggles to start .

Mind you .. it might not be the battery .. high resistant starter drawing a lot of current .. in theory a slightly down battery might struggle to turn it fast enough .. when all else fails .. what ever is left etc etc .. logical anyways .

cubasteve · 4 Jun 2018

Battery problems

hi cvega . I've used these people ; Cartronics , car electronic specialist 01932800800 at 22 High Road , Byfleet , Surrey KT14 7QG .
Cuba :bandit: :bandit: :bandit:

cvega · 11 Jun 2018

deMort, thanks for your help so far... update;

I've had a look and pulled off the carpet covering the space behind rear seats. I found the steel plates covering some electrical gubbins there but I can't say I've seen a battery sitting there. I didn't take the covers off as my time was limited, but I took some pictures, maybe they'll shed some light... battery still drains.. drove the car on Friday, 12.8V when switching it off, 11.5V by Sunday... still started and drove ok..

The one thing that HAS changed is that i got the voltage regulator replaced on the alternator (as previously the votage would drop slowly when driving the car from just under 14 to barely above 12 in a space of a 10-20 miles .. could that be done wrong and mess something up ??

pics of the rear seat area: (sorry for bad pictures)
LEFT SIDE

RIGHT SIDE

eabeukes · 11 Jun 2018

cvega said:
I don't know where to look for the tracker. Can i verify that on the options list perhaps? When i was watching the meter (albeit not too closely), I didn't see draw go up and down. It was sitting at 34-37mA steadily.
.

Pull out the dashboard speakers (two hex M20? screws) - I found an ancient tracker in there this weekend which was still plumbed in drinking tiny amounts of current! Going to have to perform some surgery to find the base unit, as thats hidden somewhere I still cant find.

cubasteve · 11 Jun 2018

Battery problems

:bandit: when I had tracker problems Porsche Chiswick had the front bumper off to access part of it . That Tracker turned out to be a big headache , had a new one fitted for £1,200 and that turned out to be a dud batch , so Porsche spent another 5 hours and eventually fitted a 2nd one for free . But Cartronics fit new tractors for about £400 just another Porsche pay treble charge . Cuba :bandit: :bandit: :bandit:

cvega · 11 Jun 2018

I just had a thought.. I have this Bluetooth/aux in/ipod interface contraption called Dension 500 installed in my car. I might try to pull it out and see what happens. I found some evidence online that it caused some VW guys to kill their batteries as it wouldn't allow their radio to fully shut down. Anyone here with that kind of device?

jev911uk · 11 Jun 2018

I think if you have a multimeter and the ability to use it you can be a bit more technical about how you find the issue than playing hunt the tracker etc.

Have you ever looked at voltage drop across a fuse to see what circuit is using power?

Rather than typing a load of instructions this PDF seems to have all bases covered:

http://www.autonerdz.com/yabbfiles/Attachments/HowtodoParasiticdraintestacrossfuses.pdf

Good luck!

deMort · 11 Jun 2018

A review ..

Your discharge check shows 30 milliamps .. which isnt a discharge its normal .

Your battery on chargeing showed nearly 14 volts so thats fine .

You checked the battery and thats fine ..

So far there is nothing wrong with your car .. hmm .

Im not likeing the alternator reg bit being replaced but any fault would show on chargeing or on a discharge check .. alternators can cause a 1 amp discharge .

All i have is we missed something .. another discharge check is in order .. set it to 10 amps on the meter and try and time how long it takes to drop to 30 milliamps .

You also need to keep an eye on it for a pulsed discharge .. anything wakeing up the can system will show on the meter .. it will then go back to sleep .. rinse and repeat as it happens again .

Seen that .. been there and a total pain to find .

You also dont have a tracker .. which would have shown up on a meter but im clutching at straws here .

cvega · 12 Jun 2018

I'll do some more long term testing.

I've not tested the battery yet, although it's a brand new Bosch S5.

Drove the car on sunday, battery was 12.8. This morning, 11.5. Started oK and after barely 8 miles, battery up to 12.6. Voltage gauge in the car all the time around (slightly below) 14.

cvega · 20 Jun 2018

Left the car fully charged Le Mans (not in the car, mind you), had a call from the wife about 3 days later that the alarm is going off. No surprise when i come back car completely dead. Really p**ng me off now.. 4 days and it's completely dead on a brand new battery and no visible drain. I'm starting to think that maybe the alternator is doing something to it or not charging it properly as the voltage regulator is the ONLY thing that's changed before this started happening. Not tested it yet as i was going to, just venting. CTEK arriving in the post today so i can charge up the spare battery and open the f***ing boot... maybe i should've bought a GT86 like i was going to originally

wasz · 20 Jun 2018

Yup, things break on old cars....something not everyone appreciates when buying a 996.

Take the battery back and have it tested?

Double sure you don't have an old tracker or similar fitted? mine has one which discharges the battery over a month or so. But its not a constant drain, it must pulse now and then

I have one of these for when I leave my car for long periods until I can be bothered to change the tracker battery or rip it out.

cvega · 20 Jun 2018

I was actually thinking about installing some sort of a cutoff switch for when I dont drive the car. However.. how does it work with car outside? If I cut the power when car is locked, alarm won't be happy.

battery is a brand new bosch s5.

snb993 · 20 Jun 2018

I definitely feel your pain with this having had a similar experience in my X5 a few years ago

All pointers were to the final stage resistor / hedgehog on the HVAC fan behind the dashboard which apparently can cause the fan to run very quietly when it's all meant to be off - very common fault on the X5 E53's.... anyway changing this didn't fix it!

It cost several hundred £££'s at the independent's to find it via pulling separate fuses and leaving it overnight connected to a meter that recorded drain activity to identify which circuit was the culprit and this was eventually found to be the ipod adaptor fitted by the BMW dealer and the satnav 'waking up' to find out where it was every 15 mins or so - ironic as I had requested that they fit the ipod adapter

So I think that you are left with pulling fuses as mentioned above - maybe satnav (if fitted), and/or Dension (as you mentioned) first as these can be lived without for a few days

HTH

:thumb:

cubasteve · 20 Jun 2018

Battery problems

:bandit: cvega once this problem is sorted you will enjoy Porsche driving , I know u want to sort it yourself but Cartronics sorted out my one , turned out to be a sensor hit on a speed bump , it took them 3 hours and they didn't charge a penny because they had fitted a pcm unit and we thought that was causing problem . Cuba :bandit: :bandit: :bandit: :bandit: :bandit:

Eey_ore_9 · 20 Jun 2018

hmmm

i had a car once that was having a similar problem it turned out it was the glovebox bulb staying on as there was something wrong with the latch not closing properly so even when glovebox was closed bulb was on inside, its a long shot but check its not something like this.or take bulb out of glovebox see if battery still dies if it does its not this

battery drain.. but no drain? doing my head in

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