Parasitic drain?

[M9G UK]

Hi

My battery has been going flat approx every three weeks from not driving it, I have a new battery and a solar trickle charger plugged into the obdII port. I would expect it to last longer than that. I have done a parasitic test on it but my multimeter is showing zero, now if everything was ok i would still expect to see at a few miliamps but theres nothing.

My question is, is there something about the boxster circuit that wouldnt show a draw on the battery and the fact that only zero shows and not at least something?

Appreciate any info

Cheers

[Scubaregs]

I was expecting this to be a thread about @John K and society, but there you go.

Might be a silly question, but are you sure the solar charger is charging the battery through the OBD11 port?

[M9G UK]

6 minutes ago, Scubaregs said:

I was expecting this to be a thread about @John K and society, but there you go.

Might be a silly question, but are you sure the solar charger is charging the battery through the OBD11 port?

Well i dont think it is, its the recommended port to use the solar charger in according to AA. Ive just read another post and loads saying they are using the cig lighter, i didnt think the cig lighter was live without key but will try it.

Even still, a new battery shouldnt go flat after three weeks and i should be getting some sort of miliamps reading on the multimeter even if the system is ok

[rowbos]

2 hours ago, Scubaregs said:

I was expecting this to be a thread about @John K and society, but there you go.

Might be a silly question, but are you sure the solar charger is charging the battery through the OBD11 port?

Beat me to it, that was literally the first thing that popped into my head when I saw parasitic 🤣

As above,  certainly on my 987.2 I keep the battery in good condition with a CTEK via the footwell 12V socket...

[Paul P]

another ctek/ciggy lighter user here - think you are OK on 986's for staying live after ignition off 

Wild guess time - frunk light staying on - or worse still on when shut, off when open? 

 

[beaks]

2 hours ago, M9G UK said:

I have done a parasitic test on it but my multimeter is showing zero, now if everything was ok i would still expect to see at a few miliamps but theres nothing.

would politely suggest that you either have a problem with your DVM or you're not connecting it correctly.

all cars will draw some current when 'asleep' - so it may be worth double checking things and going again chap.

also - I'd check the voltage seen on your battery when the solar charger is connected (and it's sunny!) to see if the thing is actually working as it should.

I would strongly recommend a CTEK if you have power available to you, but of course your battery shouldn't be going flat after 3 weeks. low voltage maybe, but not flat.

cheers,

Ian B

[Richard Hamilton]

If there is nothing wrong, you will get about 40mA drain, so I agree. Check you are using the DVM properly. You need to disconnect the earth cable, and measure between the cable end and battery post. You also need to lock the car and wait 30 minutes before taking the reading. 

The cigarette lighter socket is ignition switched on early 986s, and permanent on face-lift models. 

Connecting to the OBD port should be OK. It has a Terminal 30 connection (battery +ve) and earth. 

[M9G UK]

ok thanks guys

Easiest way to check if cig lighter working with ign off is with a multimeter. Do that later

Definitely doing the drain test correct, just odd that even if system was ok that im not getting any sort of reading, definitely expect to see anywhere upto 50ma. Thats why i thought i would ask on here if there was anything significant on the electrical system of a BoXa that would stop it showing any sort of reading. Example, going to sleep and running off a separate backup power source.

I have day off on friday so will investigate more 

[K.I.T.T.]

2 hours ago, M9G UK said:

Easiest way to check if cig lighter working with ign off is with a multimeter. Do that later

 

On a 2002 986, it should be live, unless the fuse is blown. Just try pressing the lighter in and see if it works - easier than using a multimeter

As for the parasitic draw test, are your leads definitely hooked up correctly? DVMs often need a different configuration for measuring current, as opposed to volts or resistance.

I've fount the easiest way of testing on these cars is to do the following:

- Front lid open, close the latch with a screwdriver so the car thinks it's closed. Lock the car, and leave it for at least 30 minutes.
- Alligator clips for your DVM makes life a lot easier; with the DVM configured correctly, attach an alligator clip to the a conductive part of the earth cable at the chassis ground (not battery end).
- Loosen the -ve terminal bolt enough so the terminal can just about rotate, but do not remove -ve lead
- Touch the other test lead / alligator clip to the top of the -ve post, practically perpendicular to the battery
- Remove battery cable from the battery, sliding it up "through" the lead referred in the previous step - make sure this lead is always in contact with the -ve post or your alarm WILL go off and it's fekking LOUD!
- You should get a reading on your DVM

Circa 50 mA is acceptable for these cars. Generally, you'll see not much less than 45 mA. I have a high resolution meter, and it fluctuated from around 40 to 60 mA. Much more than 60 suggests an issue.

 

How old is your battery? Have you checked the voltage during cranking?

[Stu67]

Hi,

Check the fuses in you DVM, all to easy to pop them especially if starting on the low current setting. K.I.T.T's explanation is the best way to avoid a high inrush current draw that will almost certainly take out the protection fuses in your DVM.

Stu.   

[M9G UK]

8 hours ago, K.I.T.T. said:

On a 2002 986, it should be live, unless the fuse is blown. Just try pressing the lighter in and see if it works - easier than using a multimeter

As for the parasitic draw test, are your leads definitely hooked up correctly? DVMs often need a different configuration for measuring current, as opposed to volts or resistance.

I've fount the easiest way of testing on these cars is to do the following:

- Front lid open, close the latch with a screwdriver so the car thinks it's closed. Lock the car, and leave it for at least 30 minutes.
- Alligator clips for your DVM makes life a lot easier; with the DVM configured correctly, attach an alligator clip to the a conductive part of the earth cable at the chassis ground (not battery end).
- Loosen the -ve terminal bolt enough so the terminal can just about rotate, but do not remove -ve lead
- Touch the other test lead / alligator clip to the top of the -ve post, practically perpendicular to the battery
- Remove battery cable from the battery, sliding it up "through" the lead referred in the previous step - make sure this lead is always in contact with the -ve post or your alarm WILL go off and it's fekking LOUD!
- You should get a reading on your DVM

Circa 50 mA is acceptable for these cars. Generally, you'll see not much less than 45 mA. I have a high resolution meter, and it fluctuated from around 40 to 60 mA. Much more than 60 suggests an issue.

 

How old is your battery? Have you checked the voltage during cranking?

sweet thankyou very much for that, didnt think about the frunk latch, good shout. Battery is brand new, havnt tested on cranking, will go through  on friday as i have a day off work. 

Ive experienced the alarm at 6.30 in the morning on may occasions, oh and so have all my neighbours, both alarm horns are disconnected at the moment until this is sorted

Thanks for taking the time to reply, appreciate it 🙂

[M9G UK]

Thankyou guys

The confirmation that there isnt anything unusual with the BoXa circuit is exactly what i needed to hear so i know i should be getting anything upto 50ma

Will go through on friday and let you know if i find anything

Thanks very much for all your help and advice, really appreciated 🙂

[Richard Hamilton]

This document may help:

http://www.richard-hamilton.co.uk/misc/porsche/986_Battery_drain.pdf 

[M9G UK]

17 hours ago, Richard Hamilton said:

This document may help:

http://www.richard-hamilton.co.uk/misc/porsche/986_Battery_drain.pdf 

thankyou 🙂

 

[M9G UK]

I get hooking up the multimeter, locking the car, waiting 31 minutes but what i dont get is how do you then get inside the car to remove the fuses one by one if you cant unlock the car when testing?

[BBB]

3 minutes ago, M9G UK said:

I get hooking up the multimeter, locking the car, waiting 31 minutes but what i dont get is how do you then get inside the car to remove the fuses one by one if you cant unlock the car when testing?

When I've seen this done on YouTube videos, they keep the door open, but close the locking mechanism inside the door with a screwdriver so the car thinks the door is closed.

[M9G UK]

2 minutes ago, BBB said:

When I've seen this done on YouTube videos, they keep the door open, but close the locking mechanism inside the door with a screwdriver so the car thinks the door is closed.

good idea but i suppose if i do that and the car thinks its all locked up and i get in to look at fuses surely the alarm is armed 

[BBB]

Yep, that's true. Maybe tape over the movement sensors? By all accounts they are not very sensitive anyway.

[Paul P]

1 hour ago, BBB said:

Yep, that's true. Maybe tape over the movement sensors? By all accounts they are not very sensitive anyway.

on the 987 a quick double press on the key fob will lock the doors but disarm the interior sensor for alarm - so maybe the same on the 986

[½cwt]

1 hour ago, BBB said:

Yep, that's true. Maybe tape over the movement sensors? By all accounts they are not very sensitive anyway.

Hmmm, they may be more sensitive than you think,  I had a small spider set my alarm off.  Wouldn't ahve believed it if I hadn't spotted it as soon as I opened the door after cancelling the alarm.  I evicted the non-rent paying creature immediately.

[Scubaregs]

3 minutes ago, ½cwt said:

Hmmm, they may be more sensitive than you think,  I had a small spider set my alarm off.  Wouldn't ahve believed it if I hadn't spotted it as soon as I opened the door after cancelling the alarm.  I evicted the non-rent paying creature immediately.

I bet that spider thought you were co-drivers, you heartless B'stard. 😂

[½cwt]

6 minutes ago, Scubaregs said:

I bet that spider thought you were co-drivers, you heartless B'stard. 😂

No it was on the driver's side, had to go before it got too many ideas.

[M9G UK]

2 hours ago, Paul P said:

on the 987 a quick double press on the key fob will lock the doors but disarm the interior sensor for alarm - so maybe the same on the 986

Ah ok will have a look, thanks

Hopefully someone will come along and say exactly how to test the fuses with the car locked

Also, how can i tell if i have a MY01 or 02? as this determines how long i have to leave the car standing before i test

[Paul P]

Door open with screw driver in the latch so it thinks it’s shut. 
 

or window open and lean in. (Can’t imagine that’s easy ) 
 

 

[½cwt]

1 hour ago, M9G UK said:

Ah ok will have a look, thanks

Hopefully someone will come along and say exactly how to test the fuses with the car locked

Also, how can i tell if i have a MY01 or 02? as this determines how long i have to leave the car standing before i test

It is also coded in the chassis numbers, digit 10 will be 1 for an '01 car and 2 for an '02 car.  As an approximate guide MY01 ran from about Aug 2000 to July 2001 and 02 Aug 01 to July 02 give or take a couple of weeks.  Assume about 3-4 weeks from production to registration so if you have a 51 plate it is likely to be an '02 car.  02 plate definitely an '02 car.