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Ctek battery sense

Posted: Mon Jan 15, 2018 4:58 pm
by marinaman
Evening all
Bought one of these bluetooth modules and a Ctek charger and comfort lead.
Fully charged it and after 2 weeks am down to 60% , not been in car except to open door once.
It seemed to last about 4 weeks before i fitted this battery sense and the comfort lead with the little lights on it

I wonder if something else is draining the battery, i have an automotive current tester that Maplins sell where you push it in the fuse hole you want to test and put the fuse you removed into the tester to compete the circuit.

As there are so many circuits and fuses are there any where i should start and fuse number if possible.
Also do i need to sit in the car 15 mins for it to sleep so i can then test the circuits or is there a way to overcome this situation
Thanks

Re: Ctek battery sense

Posted: Mon Jan 15, 2018 6:04 pm
by X5Sport
The little orange LED next to the ‘P’ symbol will tell you if the car has gone to sleep (it goes out).

I would be very surprised if the CTEK device draws very much at all as it is only a small bit of logic and a flashing LED - so a very few mA at most.

Cold weather will lower the capacity of the battery and I find the CTEKs a bit pessimistic overall - but that saves you getting caught out.

I wrote this back in 2012 (Post 2) covering how to check the current draw.  It should be well below 100mA and preferably below 80mA asleep I think.

Re: Ctek battery sense

Posted: Mon Jan 15, 2018 6:08 pm
by snrbrtsn
What model of Ctek ?
The unit I have tells you if the battery is good and holding charge!

I refer to the above as it suggests your battery is not..... granted the past 4 weeks has been horrendous weather whilst the car will shutdown after 16mins the alarm system is still active.

Regardless, I wouldn’t rush out and replace battery.
I leave my X5 for 3-1/2 weeks at a time, use it little when home, though even after a full battery recondition I still come home to circa 60% charge, (80% is considered a good state of charge) first night home I connect the ctek and charge overnights get to restore full health, the alternative is taking it out for a run, but that would involve getting things dirty!

Re: Ctek battery sense

Posted: Mon Jan 15, 2018 7:09 pm
by marinaman
i got the 5amp one.  charges the battery fast and shows good    only bought it ladt April big bosch 90ah jobby

so do i need to sit in car and wait 15mins before testing any circuit for draw ? and there should be nothing combined added up to 80 to 100 ma overall

just read your old pist X5. so may have to follow unless this gadget will do it

Re: Ctek battery sense

Posted: Mon Jan 15, 2018 7:23 pm
by X5Sport
The car does need to be asleep so that you can confirm the current draw.  You don’t need to sit in it but you will need access to the boot because you will need to disconnect the negative from the battery in order to measure the current flow.

The circuit tester sounds like all it detects is a blown fuse and that is all. It won’t tell you the current being drawn from the battery, that needs a meter in circuit at the battery or a device called a current clamp (it measures the magnetic field that the current generates to give you a reading).  The clamp simply goes around the battery cable (usually the positive) and you don’t disconnect anything.

Re: Ctek battery sense

Posted: Mon Jan 15, 2018 11:26 pm
by marinaman
is this device i got then not correct for testing the amps draw from the fusebox ?

From what i understand you plug it in to the removed fuse, put the removed fuse in the tester to complete the circuit
do i need to follow your method as well to find out what may or may not be drawing current

if it is,  i presume i need to sit in car for 15 mins till asleep. what circuits would be good to start with that maybe more prone to draw amps.

https://www.amazon.co.uk/Sealey-TA120-C ... ent+tester

Image

Re: Ctek battery sense

Posted: Tue Jan 16, 2018 6:05 pm
by X5Sport
The problem is that some of the fuses (and there are two boxes) power multiple systems and some systems have multiple fuses.  First thing to check is what the ‘asleep’ current draw is to prove whether you actually have an issue to chase down in the first place.

You can also end up pulling a fuse which then wakes the car up - then you have to start all over again!  It can be a real pain tracking these issues.

That device will tell you what is on the circuit so is of use  :)

Re: Ctek battery sense

Posted: Tue Jan 16, 2018 7:34 pm
by marinaman
Thanks for advice X5    so your method is the right one to start with is it to see what if any is being drawn off when asleep.
just checking on the method.  if i need to start fuse pulling and need to open the pass door to access the fuse box  do i have then to wait a further 16 mins so it sleeps again with door open ?

Re: Ctek battery sense

Posted: Tue Jan 16, 2018 7:50 pm
by X5Sport
Yes.  Alternatively just take the key out and wait 16 mins with the doors etc open.  It will still go to sleep.  :)