Parasitic drain

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colin machin
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Parasitic drain

Post by colin machin »

Hi. I have a 2007 Citroen C5 2.2 hdi. I have a parasitic drain which is draing the battery over night. I have checked the inside fuse box, and the 10 AMP fuse on the top row next to the HS fuse, when the car is put to sleep it registers 45 milliamps, does anybody know what the 10amp fuse supplies or have the wiring diagram for this?

Any help would be greatly appreciated.
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GiveMeABreak
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Re: Parasitic drain

Post by GiveMeABreak »

Which fuse box? - There are several in the engine bay and several attached to the BSI.

The fuses are marked - 10A won't help much - we need the fuse number which is clearly marked next to the fuse on the box if you shine a light on it.

Also pop your VIN up for the C5 - the fuses can vary depending on model.
RichardW
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Re: Parasitic drain

Post by RichardW »

45mA is only 0.45Ah over 10 hours - that's not enough to drain the battery. A 2007 will shut everything down after a few minutes when the BSI goes to sleep - so unless some aftermarket kit has been added, then it's unlikely to be a power drain problem - more likely the battery is shot. You need a drain of 2-3 amps to flatten a healthy battery overnight.
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xantia_v6
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Re: Parasitic drain

Post by xantia_v6 »

Yes, 45mA is probably within the normal range for modern vehicles, Are you sure that your battery has not expired?
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white exec
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Re: Parasitic drain

Post by white exec »

Do the check on parasitic drain at a main battery terminal, if that is possible.
Agree with the above; drain on XM (for example) is approx 32mA max, which is harmless.
colin machin
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Re: Parasitic drain

Post by colin machin »

hi i have put the multi meter in line with the battery and the reading is a drain of 0.02 .i will have to start pulling fuses
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GiveMeABreak
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Re: Parasitic drain

Post by GiveMeABreak »

Also don't forget that depending on what Head Unit you have (we still don't have your VIN so can't tell) this may continue to operate after the vehicle is locked for some time (internal cooling fan for example). You'll also have to wait a good 10 minutes or so to check the drain to allow the BSI and other ECUs to complete their data writing and allow the networks to sleep. Also if you need a door open, you will have to flick the door lock latch shut to fool the BSI into thinking the door is closed or the RCD circuit will be live (waking of the data networks / suspension levelling) etc.
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white exec
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Re: Parasitic drain

Post by white exec »

0.02A (20mA) is a quite acceptable quiescent battery drain.
You probably won't be able to reduce that figure much, without disconnecting things.
Pulling fuses is the right way to diagnose, though.

Battery might be self-discharging, with age.
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moizeau
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Re: Parasitic drain

Post by moizeau »

In the time it normally takes to discharge, disconnect the battery for the same period of time. Reconnect (observing the battery reconnect procedure) and see if it's OK or as before. Easiest way to check the battery condition in a discharge scenario without specific tools.
colin machin
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Re: Parasitic drain

Post by colin machin »

hi at the moment the battery is holding its charge it is a new battery .the battery drain is 0.o2 at the moment and i know it sounds daft but i only drains over night when its be low freezing .i will after wait ti the temps drops and test it when its freezing .any suggestions welcome
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GiveMeABreak
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Re: Parasitic drain

Post by GiveMeABreak »

Don't forget your alarm, which, depending on option (again I can't be specific without your VIN), may include the volumetric sensors in the cabin. The system is also monitoring and waiting for a remote unlock wake up request, and if you have TPMS installed, these also poll regularly.
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Re: Parasitic drain

Post by wheeler »

0.02 amps is well within spec. On a mk 1 C5 a top spec model should only draw around 0.06 amps.
Can your meter record max & min ? might be worth leaving it on for a few hours & see if something is waking it up as the 0.02 amps is not your problem.