Battery draining

[smayles]

Despite fitting a new heavy duty battery on my 2003 E85 last year (Halfords - 5 year guarantee) and keeping it on a Ctek trickle charger when not in use, my battery is refusing to hold a charge. Local garage have identified a "parasitic drain" (whatever that is) but can't find where or what it is. Does anyone have a similar experience or any ideas what it might be? I am guessing this could be a "how long is a piece of string" question, but somebody might be able to help. Cheers.

 

[Smartbear]

Despite fitting a new heavy duty battery on my 2003 E85 last year (Halfords - 5 year guarantee) and keeping it on a Ctek trickle charger when not in use, my battery is refusing to hold a charge. Local garage have identified a "parasitic drain" (whatever that is) but can't find where or what it is. Does anyone have a similar experience or any ideas what it might be? I am guessing this could be a "how long is a piece of string" question, but somebody might be able to help. Cheers.

Hi, you need the services of an auto electrician if you’re not experienced-a parasitic drain is an electrical load that’s not supposed to be there when the cars turned off & can be caused by various electrical circuits developing a fault.
An inductive clamp or ampmeter will tell you how large it is, a dormant car should be drawing less than 0.5A I would have guessed? :?
Rob

 

[Ducklakeview]

The car should draw around 30-40ma max after it's gone to sleep. Half an amp will drain the battery over a couple of days. Do you have a CD changer or sat nav DVD drive, have seen a couple of cars where this has been the drain.

Mike

 

[Zoomer]

Or perhaps you have something nonstandard that the previous owner has installed such as Bluetooth or camera that isn’t switching off.

 

[kis]

An ampmeter will tell you how large it is, a dormant car should be drawing less than 0.5A I would have guessed? :?

Hmm interesting. Where would I connect the amp meter? Got access to one at work. I’ve noticed battery can drain quick. But then I do have sat nav and a cd changer lol

 

[Ewazix]

Besides the common stereo issue, aftermarket one-touch roof modules have been regular culprits. Besides that the potential list is endless and requires simple but methodical work with a meter.

 

[Courageous]

OOh where did my reply go? I posted the same as Mike - had the same issue with a Dodge and it turned out to be the radio. Pull the fuse on that and wait a few days.

 

[ph001]

Buy yourself one of these and you can just clamp it around individual wires to look at the current... https://www.amazon.co.uk/Multimeter-Tacklife-Auto-ranging-Continuity-Capacitance/dp/B01N014CTB/ref=pd_sbs_328_4?_encoding=UTF8&psc=1&refRID=P4ZT794ZEEJEHQG793MJ&tag=z4fo-21

If you are getting a flat battery in 2 days (assuming from 77Ah fully charged) I would expect to be seeing a discharge somewhere in the region of 1-2A. That's bang on for something like a cd changer, dvd, aftermarket module etc. Maybe an interior light at a push (the one on the centre console is defo worth a check as the switch plunger can break off).

If you just have a basic voltmeter, you can look at the voltage across each of the fuses in the fusebox (make sure the car is asleep first by sitting in it for 10 mins, locked with the interior alarm sensors disabled (long press on the lock button after initial lock)). The fuses have test points on the top of them so you don't have to remove them but you will need sharp pointy probes.

A 5A fuse is about 20mohms resistance, so if the fuse had 1A flowing through it, you would see 20mV on your voltmeter. The voltage reading across each of the fuses should be only 1 or 2 mV at most. Anything more than that and, the respective circuit needs investigating.