Batt drain problem

Hi everyone. A friend has a VW Polo twist 2004 which drains the battery every
two days or so when the vehicle is standing idle. So she has been told by the
VW garage the problem is the car radio - called an 'Alpine'. What the problem
is they dont say but they do know they want £50+/hour to sort it out! How can
I check this out? I'm a competent mechanic with a background in electronic
engineering. So it should be easy but I would really appreciate some guidence
on where to start or some ideas on where the problem is most likely to be. I
just dont want to start pulling the facia apart and possibly create more
problems. Many thanks and a happy new year to all.

UKD

--
RD

Message posted via CarKB.com
http://www.carkb.com/Uwe/Forums.aspx...ooled/200712/1

To be honest, even if the radio remained on for two days, it does not draw
enough current to drain a car battery of any decent capacity.

Since you are electronically inclined, measure the current the battery is
drawing while off. See if what the VW Garage is saying makes sense. It
would have to draw more than an amp to significantly drain a battery in two
days.

If it is drawing that much current when off, makes sure no short in the
wires upstream of the radio. If not disconnect the radio, again check the
drain on the battery.

If not drain, get rid of the radio, might me in warranty if a 2004. Even so
aftermarket radios are often cheaper and better than originals. Or go to a
boneyard and pick one up very cheap.

This should do it......let us know.

Joe

"ukdodger via CarKB.com" <u20620@uwe> wrote in message
news:7d5f6a4eea4a9@uwe...
> Hi everyone. A friend has a VW Polo twist 2004 which drains the battery
> every
> two days or so when the vehicle is standing idle. So she has been told by
> the
> VW garage the problem is the car radio - called an 'Alpine'. What the
> problem
> is they dont say but they do know they want £50+/hour to sort it out! How
> can
> I check this out? I'm a competent mechanic with a background in electronic
> engineering. So it should be easy but I would really appreciate some
> guidence
> on where to start or some ideas on where the problem is most likely to be.
> I
> just dont want to start pulling the facia apart and possibly create more
> problems. Many thanks and a happy new year to all.
>
> UKD
>
> --
> RD
>
> Message posted via CarKB.com
> http://www.carkb.com/Uwe/Forums.aspx...ooled/200712/1
>

> To be honest, even if the radio remained on for two days, it does not
> draw enough current to drain a car battery of any decent capacity.

Depends how loud you leave the volume :-)

Anyway, don't discount the radio. A bloke I worked with had exactly the
same problem. Turned out that the radio was drawing significant current,
even when 'off'.

Having removed it, he found that one of his kids had been 'posting' coins
into the cassette slot, and one was causing a partial short around the
power input :-)

Al.

On Fri, 28 Dec 2007 18:06:58 GMT, "ukdodger via CarKB.com"
<u20620@uwe> wrote:

>Hi everyone. A friend has a VW Polo twist 2004 which drains the battery every
>two days or so when the vehicle is standing idle. So she has been told by the
>VW garage the problem is the car radio - called an 'Alpine'. What the problem
>is they dont say but they do know they want £50+/hour to sort it out! How can
>I check this out? I'm a competent mechanic with a background in electronic
>engineering. So it should be easy but I would really appreciate some guidence
>on where to start or some ideas on where the problem is most likely to be. I
>just dont want to start pulling the facia apart and possibly create more
>problems. Many thanks and a happy new year to all.
>
>UKD

You need to measure parisitic drain (that is the drain when the key is
off, doors closed, everything off that you would normally turn off).
You must let it sit, measuring the drain for at least an hour or so,
with periodic checks to see what the drain is. Chart these, make a
log, whatever.

Any drain over 70 MA (that's 0.070 amps) is considered to be high, but
you will probably find that there is an initial high drain that goes
away after about 5 to 15 minutes. This initial high drain is normal.

He has replaced the battery, hasn't he?

'he found that one of his kids had been 'posting' coins
>into the cassette slot'


You gotta laugh. Thanks for you help

UKD

--
RD

Message posted via CarKB.com
http://www.carkb.com/Uwe/Forums.aspx...ooled/200712/1

No she hasnt actually Pete. But why would an old battery be prone to draining?
Thanks for your help.

UKD

--
RD

Message posted via CarKB.com
http://www.carkb.com/Uwe/Forums.aspx...ooled/200712/1

Thanks Joe. Good practical advice. Cheers

UKD

--
RD

Message posted via CarKB.com
http://www.carkb.com/Uwe/Forums.aspx...ooled/200712/1

On Fri, 28 Dec 2007 22:10:46 GMT, "ukdodger via CarKB.com"
<u20620@uwe> wrote:

>No she hasnt actually Pete. But why would an old battery be prone to draining?
>Thanks for your help.
>
>UKD

Well, it's getting along in years, so to speak. Not unreasonable to
have it go at 4 years, which is right about... now!

That would be my first guess.

I have seen that!
Battery could charge up but would not hold a charge over time with nothing
connected to it.
I could measure voltage on the battery case! It helped after I cleaned up
any acid on the case, but the battery was just bad.

Always check the part before buying another! <g>


"ukdodger via CarKB.com" <u20620@uwe> wrote in message
news:7d618b280150f@uwe...
> No she hasnt actually Pete. But why would an old battery be prone to
> draining?
> Thanks for your help.
>
> UKD
>
> --
> RD
>
> Message posted via CarKB.com
> http://www.carkb.com/Uwe/Forums.aspx...ooled/200712/1
>

start with the easy stuff.

glove box light
trunk light
unplug the radio for a few days and see what happens.



Polo... I have no clue what they look like. Just not a USA vehicle.

"ukdodger via CarKB.com" <u20620@uwe> wrote in message
news:7d5f6a4eea4a9@uwe...
> Hi everyone. A friend has a VW Polo twist 2004 which drains the battery
> every
> two days or so when the vehicle is standing idle. So she has been told by
> the
> VW garage the problem is the car radio - called an 'Alpine'. What the
> problem
> is they dont say but they do know they want £50+/hour to sort it out! How
> can
> I check this out? I'm a competent mechanic with a background in electronic
> engineering. So it should be easy but I would really appreciate some
> guidence
> on where to start or some ideas on where the problem is most likely to be.
> I
> just dont want to start pulling the facia apart and possibly create more
> problems. Many thanks and a happy new year to all.
>
> UKD
>
> --
> RD
>
> Message posted via CarKB.com
> http://www.carkb.com/Uwe/Forums.aspx...ooled/200712/1
>