Battery drain

[Henry A Harper III]

I would guess that a net draw of any more than a few hundred milliAmps (say
0.2-0.5 Amp) will drain a battery fairly quickly.

-----Original Message-----
From: dgraber460 at aol.com [mailto:dgraber460 at aol.com]
Sent: Saturday, August 21, 2010 3:47 PM
To: hah at alumni.rice.edu; quattro at audifans.com
Subject: Re: Battery drain


Thanks a bunch for the response.
Its quite a spark at hook up. More than should be. I have had a battery
hydrogen flash (explode) on me before so I am very careful about that.
What amp flows am I looking for? What is normal and what is "found the
bastard!".


Dennis
Denver


-----Original Message-----
From: Henry A Harper III <hah at alumni.rice.edu>
To: dgraber460 at aol.com; quattro at audifans.com
Sent: Sat, Aug 21, 2010 3:32 pm
Subject: RE: Battery drain



What you are looking for is *current* flow through the DVM, between the
battery post and harness terminal normally on the post. Set DVM to measure
Amps. You may need to change where one of the DVM wires plugs in. You may
notice a limitation/warning printed  on the DVM of say 10 Amps before you
blow a fuse inside the DVM, in that case be careful not to do anything in
the car that will take that much power - interior lights will probably be
fine, but headlights and A/C would be too much.

Meauring 11.7 Volts across the gap between battery post and harness terminal
is about what you'd expect from a flat battery. How much of a spark does it
make when you hook it back up (in a well-ventilated area of course)?

> -----Original Message-----
> From: quattro-bounces at audifans.com
> [mailto:quattro-bounces at audifans.com]On Behalf Of dgraber460 at aol.com
> Sent: Saturday, August 21, 2010 3:19 PM
> To: urq at audifans.com; quattro at audifans.com
> Subject: Battery drain
>
>
>
> Well one of my worst nightmares has apparently come to pass.
> My battery goes flat after ~ 12 hours. I had the battery checked
> this morning and they said it needed a charge but was not the
> problem. I'm not totally convinced by their testing method, but whatever.
> I remember seeing a post about taking the battery post off, and
> checking the power drain across the post and cable with a DVM
> with everything turned off, then pulling fuses 1 at a time till
> you find the culprit. Is this the method of choice? Am I right
> that you measure across the disconnected cable and the post for
> voltage drain? What is considered normal here for clock, ecu,
> radio, and misc "maintenance".
> I'm seeing 11.7 volts across here which tells me something is
> _way_ wrong and not a small short to ground. More like leaving
> the lights on all day?
> Dang - I _hate_ electrical short issues!! I would rather have a
> mouth full of root canals than deal with this!!
> Patient is an 83 URQ with a 3B motor transplant.
> Help!!
>
> Dennis Graber
> 720-838-0558
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