my hubby has a 2004 tdci 1.8 ghia focus, he works away for two weeks
at a time and when he comes back the battery is flat
we had a auto electrician look at it and nothing obvious was showing ,
the alarm and immobilisor are on all the time he is away , would they
drain the battery ?????
this is the second new battery in as many months , the alternator
seems to be charging ok ,it starts every day when he is home after the
initial starting with battery boost pack
any help would be appreciated ...thanks
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You probably have a parasitic drain on the battery somewhere, like a
door switch, glove box switch, vanity light switch, etc. Usually the
switch is stuck on and the battery gets drained. All anyone needs is
a simple test light to help isolate the cause of the drain, but you
have to know what you're doing. So when your auto electrician says
"nothing obvious is showing" he means he's not going to figure it out
for free if it doesn't jump out at him and bite him in the face.
Can't blaim him, he needs to eat as well, right?
You have a parasitic drain and most likely it is caused by your alarm. Try
hooking the fcar up to maintainer while he is away on his trips. It will
keep the battery fresh and is alot cheaper than buying a new battery every
few months. Easiest thing to do though would be to just put a quick
disconnect on the battery so that when he leaves, he can quickly disconnect
it and no problems when he gets home.
To check for parasitic drain, get a Digital Volt Meter that also measures
Amps. With the DVOM set to measure Amps (A=) and with the key off, take the
negative battery cable loose. Put one lead on the negative battery terminal,
and touch the other lead to the negative cable, or the engine block. If that
meter reads over 50mA (mA=MilliAmps) or .05Amps then the drain is too high,
and you need to disconnect the battery for long sitting periods. It doesnt
take much to drain a battery completely with a decent drain on it, but it
takes 100Ah (amp hours) to charge a battery back up to full capacity. Thats
charging 1 amp for 100hrs. So if you have a 5amp charger it would take 20hrs
to charge a battery back up to full capacity.
Hope this helps...
replying to Ford Tech, J.Zimmer wrote:
Thanks for pointing me in the right direction.
I recently tracked the "parasitic drain" down to Microsoft Sync & Satellite
Radio in my 2007 Ford Focus. Removed both fuses from the panel inside the
vehicle, to disable those systems, and the eliminated the power drain completely.
Thanks again for the following past input.
Using trhe same formula in the reply from Ford (capacity / charge rate charge time), the 0.05A drain would take more than 83 days (capacity / drain
rate = depletion time) to deplete the same battery. If the battery is weak
and cannot support the 0.05A load, then it will be dead over a long weekend
of non-use. If the car can start when used daily, but does not start after 3
or so days of being parked, then the battery is no longer able to hold the
charge, and the normal and customary parasitic loads are not the problem.
Pulling fuses will buy a couple of extra weeks because the drains are gone,
but the battery will hold the charge for shorter and shorter periods, even
with the static loads taken away.
If the person posting, it looks like J. Zimmer, has the factory battery in
his '07 Focus, I'd suggest that the battery is no longer capale of holding a
charge, and is screaming to be replaced.
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