Power Drain Inevitable

**Red_Beard** · 10-03-2007, 10:27 PM

At first, I thought it was just my Carnetix P1900 wasn't on Deadman Timer mode, but its still draining the battery.
The scary thing is, I don't know what is draining it. It could be so many things.
I have roof lights, front aux lights, cb, radio with elongated wires (plenty of crimps) and the mac mini hook up.

Any ideas how to go about looking for a short circuit?

My Carnetix is put on a very good ground (its on the bare car body, which is the ground) -- will this short circuit to the ground? I remember seeing a spark when first put it there. You think the case is making a circuit?

Its so weird. I was playing around with the power stuff trying to narrow it down, but its hard to tell. It would idle and have plenty of power. I drove through the woods with all the lights on and the volt meter on the dash was reading below start voltage! So, there's some serious drain somewhere.

**Uraijit** · 10-04-2007, 01:52 AM

Start by disconnecting the PSU. If it doesn't drain it, then something is wrong with your computer setup. If it still drains, then pull the fuse on your other accessories, one at a time, until something stops the draining. Then trace it out. If you're reading low with your lights on, while driving, it's probably the lights...

**Phatsacks** · 10-04-2007, 04:53 AM

My buddy swears his battery drain is due to the P1900.

He disconnected his carpc and his battery still dies (but the P1900 is still connected)

**Uraijit** · 10-04-2007, 05:46 AM

Originally Posted by Phatsacks

My buddy swears his battery drain is due to the P1900.

He disconnected his carpc and his battery still dies (but the P1900 is still connected)

Then why doesn't he disconnect the P1900, and see if it changes? He probably just has a bad battery.

**Phatsacks** · 10-04-2007, 12:12 PM

Yeah, I was trying to tell him that some batteries are bad when they die often like that, but he said it was new, and he even had it tested.

I'm rather certain he did isolate the carnetix 1900 issue, but I just don't see how it can use power other than the fan if nothing is connected.

**speakermakers** · 10-04-2007, 11:34 PM

At my job I deal with charging systems and vehicles that have current draws every day. The most common mistake that people make when attempting to track down a parasitic draw is that they don’t realize that damage may have already been done to the battery due to deep cycling (over draining). It only takes a couple of deep cycles to damage a typical battery to the point that it will no longer hold a charge, even with nothing hooked up to it. The fastest and most accurate way of finding a draw is to use a multi meter with a 10 amp or greater setting placed in series with the battery and then disconnect one item (fuse for that item) at a time until the current drain goes a way (less than .02 amps typically).
For further information on this do a goole search for “parasitic drain” or reply here and I can give more detailed info. Its worth mentioning that due to the specific operation of computerized factory equipment in vehicles produced within the last 10 years or so the procedure for this test is specific to the make and model of the vehicle. Assuming that it is that new.