I replaced my stock battery with an Optima red top about a year ago. Last week on Monday I came out to my garage to start my car after it had been sitting since Thursday afternoon. Battery was dead. Turns out I had left my dome light on. :failboat: Called a friend and had him come over and give me a jump, and things seemed fine.

This morning I came out to start the car after it had been sitting since Friday afternoon, and I got the same thing! Dead battery... But this time I had not left anything on. This is the first time this has happened. The only electrical change I've made since I got the battery was to hardwire the power adapter for my new Garmin GPS. I bought an add-a-circuit and tapped it into fuse number 4 (cigarette lighter) with a 2 amp fuse, then soldered that to an add-on cigarette lighter and plugged the power cable into that. Seems fine, and as far as I can tell, that circuit shuts off when the car does... So I doubt leaving the GPS in (but not on) is draining the battery.

Alternator seems fine... My SM3 is reporting 13.6-13.8 volts while driving/idling. I would expect a few tenths more, but I'm basing that expectation solely on my previous vehicle, so I may be way off.

At this point I am faced with just making sure that I start the car at least once per day, or disconnect the battery if I'm going to let it sit... Is it possible that the red top is toast? I would have expected it to be able to handle a few complete drains.

The Red Top should not have been damaged by the discharge, but it would be a good idea to have it tested.
Also you should perform a standby/parasitic drain test by connecting an ammeter between one of the battery terminals and the post. With the key out and car locked you shouldn't see more than about 50ma of drain. If it's much higher you can then begin disconnecting things by pulling fuses one at a time until you see the drain drop back to normal. The culprit will be on the circuit with the last fuse you pulled.
One thing you can check first is the trunk light. If it's staying on it will drain the battery in a couple of days.

try having the battery charged (not just by the alternator) and then see how it does. Definitley check the parasitic drain on the battery as Mulder said, too.

yea, parasitic drain will kill the best of batteries...

might also be a good idea to just throw it on a battery charger to make sure it's nice and topped off. Maybe the car wasn't running long enough to give it a good charge

Thanks, Mulder! Just the man I wanted to hear from...

I'll perform a parasitic drain test and report back with results if they're worth mentioning.

Test results:

Meter set to 200mA, I got 3.5. That can't be right... It's been a while since I used one of these things to measure current. Do I need to multiply that number by 10? 100?

Well I don't know what kind of meter you were using, but that doesn't sound right. Is it an autoranging meter or manual? Did you have the leads connected to the proper terminals?

Here's a pic of the multimeter and how I had it set up. It's nothing fancy, but it's worked for me so far.

http://i226.photobucket.com/albums/dd240/rrarey/mm.jpg

Looks like you've got the positive lead in the wrong hole. The 10A plug is only for use with the 10A scale, for the other current ranges you have to put it in the V/ohm/ma plug.
Also be sure when doing this test NOT to turn on anything in the car that will draw a lot of current or you may damage the meter.

That's what I thought... But when I used that hole, I got "00.0" which I know isn't right.

EDIT: Looks like at some point in the past 4 years I blew the internal fuse on the multimeter... That's why I wasn't getting a reading.

I found my grandfather's old analog meter and hooked that up properly... I'm getting between 50 and 55 mA.