In article ,
wrote:

I have a slow drain on my battery and I can't track down where the
problems is. I spent this afternoon tracking down where the problem
might be. I thought it was with a modification to my lighting system
I did but I eliminated that and I'm still having the drain problem.

snip

In Kevin
McMurtrie wrote:

That's not the right way to diagnose the problem.

Pull one of the cables off the battery. Wrap one stripped wire around
the battery post and another around the cable. Put the cable back on
the battery post loosely. Attach an ampmeter (5+ Amp range first)
between the two wires. Now lift the cable off the battery and monitor
the current. It's important that the car's electrical system be
powered to 12V before sending current through the amp meter; the rush
of power would kill it. Slide the cable back on the battery while
you change ampmeter modes to avoid current surges.

Now start pulling fuses and disconnecting things. You'll see exactly
how much current each device is using by watching the reading on your
ampmeter drop.

It's possible that nothing is drawing too much power. Anything less
than 50mA is OK. That's 1.2 AH per day of drain. Batteries can self
discharge if they're in poor condition or if unpure water has been
added to them.

Thanks for this little tutorial on properly measuring the current and
troubleshooting this sort of thing. It's always good to get tips from
those more experienced.
I did that test and the initial reading was about 65mA which I'm
guessing could still be safe, yes? no?

I'm starting to suspect that it may now just be that the battery is
going on me. It's almost 5 years old, it has been used on a fairly
powerful system for 2 years, plus last week my wife had to pull over and
feed our 2 month old while she was out and she drained the battery by
trying to run the AC and fan while the engine was off. That probably
pushed the battery over the edge. Since it was down so far that she had
to ask someone for a boost.

Friday night I did disconnect the battery completely from the electrical
system and the voltage on the battery remained at 12.25V. Last night
after I got the car back together around 11PM I took it out for a quick
5 minute spin. When I got back the battery read 12.75V and with all
cables connected it read about 11V this morning. Could the battery just
not have a proper "amp" capacity now and that 65mA current is causing
that drain, whereas on a new charged battery it wouldn't be an issue?

And thanks to the other posters for the info. It's good to know that my
two amps aren't a problems. My voltmeters show that I'm getting 14.2V
when I'm running the car, so I'm suspecting that my alternator is fine,
though I guess I show check the cables running to it.

Thanks again.