Battery draining in 2-3 days

[Crizdee]

Hi,

Had the car 2012 Tekna for 18 months and it’s been fine but recently started draining the battery in 2-3 days and there’s not enough Amps to turn engine over.

Fitted new battery but still draining in a few days

So going to do a parasitic test

Any known main culprits for what causes this? Any obvious areas to look?


Chris

[calnorth]

The old chestnut was the boot lamp was remaining on. Not sure about a J10 but the IPDM unit should switch out power to the car except for security. Security consumption is extremely low so would not kill a battery in a couple of days.

Doubt we would have any accurate wiring diagrams to perform any trace.

UPDATE.....check for any DTCs present

[Deleted User 10757]

Best way is to get a suitable Amp meter that is capable of measuring a wide range.
Ideally this equipment would have a clamp that fits over the battery positive cable.
Then allow the car the settle - so that any necessary systems shut down - then start pulling fuses until you see the drop in readings on the meter.

Usual culprit is a stuck relay some place , or an interior light staying on - however poorly wired accessories can also cause a drain.

Ideally - if you go down the fuse pulling route - then identify the fused circuits that are permanently live , as these are the likely culprits

[lewisbryant]

Pulling fuses isnt the best way to do it as if you pull a fuse to a module that is in low consumption mode "sleep" and you plug the fuse back in it will then power up and will wait for a message from bcm to shutdown and enter sleep mode again which wont happen until you cycle the ignition

[Deleted User 10757]

and your solution

[Crizdee]

Hi,

Thanks for the help and details.

So connected between the negative terminal and the negative clamp it’s reading 0.108 if that means anything

I’ve pulled all the fuses and no drop!
Fuse box by the footwell
And the 2 next to the battery including the ridiculous upside down fuse box.

Pulling relays seems a bit more difficult I guess there’s a real trick for doing it.

Chris

[calnorth]

Hi,

Thanks for the help and details.

I’ve pulled all the fuses and no drop!
Fuse box by the footwell
And the 2 next to the battery including the ridiculous upside down fuse box.

Pulling relays seems a bit more difficult I guess there’s a real trick for doing it.

Chris

Whats the value of the current drain in series with battery?

[Crizdee]

Hi,

Thanks for the help and details.

I’ve pulled all the fuses and no drop!
Fuse box by the footwell
And the 2 next to the battery including the ridiculous upside down fuse box.

Pulling relays seems a bit more difficult I guess there’s a real trick for doing it.

Chris

Whats the value of the current drain in series with battery?

Hi,

I’ve got the meter between the negative terminal and them negative cable. Is that series? It’s reading about 0.108 or 00.90

I’ve just read about another way to measure without pulling fuses but measure the millivolts across each fuse once in sleep mode with the car door and bonnet switches clamped closed.

I’ll keep trying it’s all a bit new to me testing like this

Chris

[calnorth]

Its the sleep state current you need, which in your case as above might be 0.108. I assume that might be 108 milliamps? if you are on a 10 Amp range or lower. You seem to go from what looks like 900ma to 108ma? That seems to be a step change down anyway...perhaps to sleep mode.

You could assume that a 1 Amp draw on a 70AH battery would kill it in less than 70 hours...a rough approximation.

There is a post here somewhere by duncho that shows the sleep state current draw he observed. I'll look for it.

I've not had to do this kind of testing because we would normally exchange suspect units until the problem was solved. The car has 3 major electronic units which are ECU, BCM and IPDM. IPDM is of course the prime power controller for the car. It is under various computed controls.

TBH I never measured across fuses either. A voltmeter may show something small?

[lewisbryant]

Usually drop down to like 0.016ma on the qashqais but we usually use under 60ma as a good.

There are a few fuses that are a bit hidden in drivers footwell towards centre console, theres a fuse there that is for the radio I've had that twice drawing current usually about 200ma though so may be not but maybe so haha

But yeah best method is voltage drop across the fuse, you can get charts online which will convert the drop into an equivalent amperage, but have to be using the right chart for the right size fuse (mini , maxi, standard ect.) Dont forget the alternator which can leak and cause a drain unplug it and take off its positive cable to rule that out but be careful not to touch that big cable to ground!!! Got caught out on an alternator on a smart car years back wont forget about that haha also electric seats I've seen switches cause a drain by being stuck on. Big list to get through but definitely have something there with 0.108ma also good way to tell if it's in sleep mode is the handbrake button red light will go out

Also if your not very good with a multimeter to measure volt drop across the fuse you can get things like amp hound that does the conversion for you