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Acceptable Parasitic Drain
Posted: Wed Sep 18, 2019 8:14 pm
by Daytona
I’m getting 200mA, the Internet seems to suggest 50mA is the magic number.
What do you think?
Re: Acceptable Parasitic Drain
Posted: Wed Sep 18, 2019 8:25 pm
by mikep99
Seems quite high to me...
I was monitoring mine a while back and after 10 mins or so of the car being left alone (ie. locked or doors closed), the drain was about 60mA.
I assume you've been checking for a reason?
How have you checked the drain - multimeter at the battery?
ta
Mike
Re: Acceptable Parasitic Drain
Posted: Wed Sep 18, 2019 8:43 pm
by Robnic
Too high that's fifth of an amp, when presented at the garage with a job like this we generally look for under 80mA. Some newer stuff is slightly more but a B7 wants to be 60mA or less.
Re: Acceptable Parasitic Drain
Posted: Wed Sep 18, 2019 8:45 pm
by Daytona
I thought was high too.
I left it for half an hour to fully shut down but didn’t drop.
I’m checking it as it’s been getting progressively slower to turn over in the mornings, finally not starting yesterday, charged the battery and took it to be tested but as I thought, it’s fine (wants to be, only 2.5 years old)
I checked it at the battery, well made some cables up, shut the boot and connected the multimeter up outside.
Re: Acceptable Parasitic Drain
Posted: Wed Sep 18, 2019 8:47 pm
by Daytona
Oh, and disconnected the Bluetooth module under the drivers seat as I’d read that’s a favourite but made no difference.
Attempted pulling fuses but kept triggering the aftermarket alarm

Re: Acceptable Parasitic Drain
Posted: Wed Sep 18, 2019 9:01 pm
by Robnic
If you have it in the garage roll all your catches that way you can have all the doors boonet and boot open which makes things easier, there is a method of measuring milli-voltage across fuses which equates to current draw but it's a bit hit and miss.
We use an oscilloscope and amp clamp powered through the mains to avoid amp clamp battery voltage drift, oh and a thermal imaging camera over the last few years!
Can be a tricky job, good luck.
Re: Acceptable Parasitic Drain
Posted: Wed Sep 18, 2019 9:11 pm
by Daytona
I did roll the drivers door catch to trick the car into thinking it was shut but even with the OE alarm ultrasonics disabled via the button the aftermarket alarm microwave sensors were tripping.
Re: Acceptable Parasitic Drain
Posted: Wed Sep 18, 2019 9:15 pm
by Robnic
They shouldn't lock it with the blade, they can take over half hour to go to sleep fully.
Re: Acceptable Parasitic Drain
Posted: Wed Sep 18, 2019 9:23 pm
by Daytona
Blade as in key?
If so I meant I pushed the catch in on the door then locked the car with the door open via the button on the key. Are saying don’t lock it?
Re: Acceptable Parasitic Drain
Posted: Wed Sep 18, 2019 9:32 pm
by Robnic
Yes lock it with the key blade not the remote plip.
Re: Acceptable Parasitic Drain
Posted: Wed Sep 18, 2019 9:33 pm
by Daytona
Tomorrows job then

Re: Acceptable Parasitic Drain
Posted: Sun Sep 22, 2019 8:03 pm
by Daytona
Well, it was the add-on DAB radio, with that disconnected dropped to 60-90mA, (multimeter was fluctuating a lot).
Hopefully that’s low enough to not cause any issues.
Cheers all

Re: Acceptable Parasitic Drain
Posted: Sun Sep 22, 2019 8:05 pm
by mikep99
Glad its sorted!
Which DAB add on do you have?
Does it not have auto shut down after x amount of time?
ta
Mike
Re: Acceptable Parasitic Drain
Posted: Sun Sep 22, 2019 8:15 pm
by Daytona
Cheers Mike,
Just an Alpine Ezi DAB, I tee’d (properly with an add in loom) off the cd changer feed for an ignition live via a relay and expected it to that but it was the unit itself, display went off as it should but just sat there draining the battery whilst “off”!
Re: Acceptable Parasitic Drain
Posted: Sun Sep 22, 2019 8:58 pm
by Robnic
Infotainment components in general are favourite more so if aftermarket, kudos on the result.