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Battery consumption with the car off?

5418 Views 64 Replies 13 Participants Last post by  vinnypt
My battery is consuming 240mA with the car off!
I have read that the normal consumption is about 30 to 50 mA !

What could be wrong?

Thanks for all the help you can give!
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Do you have a SmartTop?
Did you buy your car used?
Any 3rd party device you know or might be unaware of like radar or car alarm or lights?
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Do you have a SmartTop?
Did you buy your car used?
Any 3rd party device you know or might be unaware of like radar or car alarm or lights?

Yes, I have instaled a Smarttop, an year ago I think!

Yes, I bought it used.

I have installed a S100 Headunit, about an year ago ! :grin:
I Have taken off all the Fuses, one by one, both in the interior fuse box as in the hood fuse box.

The problem persists !!!
Some early versions of the Smarttops had power drain issues but that was resolved. do you know when your SmartTop was made or what version?
I charge my car with a ctek 4.3 trickle charger/maintainer every week

how old is your battery? did u have same issue with any other battery?
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So how long does it take for your battery to go dead? When we bought our car last summer the dealer instructed us to put a trickle charger on the car whenever it sat for more than 14 days. This is due to the fact that a couple of the computers are never off. ( according to dealer anyway)
I have heard that bmw has a large problem with discharging batteries. Have a friend with a new x5 and he puts a trickle charger on if it sits for more than 7 days. And it has gone dead when he didn't. Of course it could be the smart top as well. I haven't put that on our car yet.
that is not a SmartTop by mods4cars. so i cannot speak for it. Majority of members have the mods4cars one.
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Some early versions of the Smarttops had power drain issues but that was resolved. do you know when your SmartTop was made or what version?
I charge my car with a ctek 4.3 trickle charger/maintainer every week

how old is your battery? did u have same issue with any other battery?

I have this one:

http://www.reinhold-engineering.de/pdf/CMR171_e.pdf


The battery is a BOSCH S4. It have 2 months old !!!
The previous battery was also a BOSCH S4 and it died in with less than 2 years old.
your new battery might have been defective or had bad cells if it was not tested prior to installation. or you maybe have an alternator not working up to par

get a ctek charger and charge weekly :D
or that other brand smarttop is draining your battery
So how long does it take for your battery to go dead? When we bought our car last summer the dealer instructed us to put a trickle charger on the car whenever it sat for more than 14 days. This is due to the fact that a couple of the computers are never off. ( according to dealer anyway)
I have heard that bmw has a large problem with discharging batteries. Have a friend with a new x5 and he puts a trickle charger on if it sits for more than 7 days. And it has gone dead when he didn't. Of course it could be the smart top as well. I haven't put that on our car yet.
The Battery goes dead in 3 to 4 days!
your new battery might have been defective or had bad cells if it was not tested prior to installation. or you maybe have an alternator not working up to par

get a ctek charger and charge weekly :D
or that other brand smarttop is draining your battery
I had charged it already, and it goes for another 4 days.
I'll disconect the smarttop for a week and see what will happen !!!

Thanks for all the help ! :wink:
i hear you but charging a 'bad' battery accomplishes nada :D
i hear you but charging a 'bad' battery accomplishes nada :D
Yes, I understand that, but...

This is the second one. It happened with the old one, and know it's happening with this new one that only have 2 months.
When I Charged it, it stays OK for 3 or 4 days.
It only happens when I don´t ride the car for 3 or 4 days...

And I already mesure the corrent with "all OFF".
For what I know 240 mA It's not normal. It should be 30 to 50 mA.

Do you agree?
Sean n others more qualified to answer that
But 4 days of no driving is common amount of time for battery to drain on our cars
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Are you able to turn off or disconnect the aftermarket Reinhold module and see if the current draw is still 240mA?
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Sean n others more qualified to answer that
But 4 days of no driving is common amount of time for battery to drain on our cars
not common, not normal ..... on my original 8 years old battery (just replaced couple months ago) I left the car parked for 2, 3 weeks at the time (sometime longer), without trickle charged, and it started right up everytime. It eventually died of old age. I also have smarttop.... the only thing is since I parked in the garage, so never locked the door. I heard something likes locked car use more battery (due to sending out signal all the time)
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not common, not normal ..... on my original 8 years old battery (just replaced couple months ago) I left the car parked for 2, 3 weeks at the time (sometime longer), without trickle charged, and it started right up everytime. It eventually died of old age. I also have smarttop.... the only thing is since I parked in the garage, so never locked the door. I heard something likes locked car use more battery (due to sending out signal all the time)
did you ever charge that 8 year old battery?
my previous battery got replaced every 2 years like clockwork (4 times) until i started charging it
did you ever charge that 8 year old battery?
my previous battery got replaced every 2 years like clockwork (4 times) until i started charging it
never charged in the first 8 years!! only installed trickle charge (just for fun, like all my projects on this car!!) after the new battery
IIRC, battery university states heat and humidity is not a car battery's friend.
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If you are drawing 240mA with all electrical items switched off then this is your parasitic drain regardless of battery condition.

The length of time your battery can handle this is an indication of it's condition.

You indicated that you removed all your fuses but the power drain was still present.
Can you confirm this as I would have expected at least one fuse to have an effect on the milliamp drain.

Are you using an amp meter in series?

I have a RC model battery charger that allows me to set a trickle charge rating from 50mA upwards in 50mA increments.

On my SLK 55 (with Smartop) the battery, when fully charged, will discharge slightly on a trickle charge of 50mA, it will almost hold power at 100mA and will charge up very slowly at 150mA. I set it at 200mA as I think my battery can handle this long term if required.
From the results that I have it looks like my battery drain when off is about 125mA so 240mA seems high.

Tell us what happens when you disconnect your roof controller.
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