HELP!! my battery is at 5 volts and horn beeps for like a second
 

OK I went and checked my battery after 5 days of not starting it and its at 5 volts so I put the charger on it and it sounds like the horn chirped for about a half of a second its done this before at random times. I'm sick of it doing this, how do I find out what's draining my battery?

For starters I would have the battery charged and tested.

After you confirm that the battery is good. Then start trouble shooting.

Its a 6month old optima red top

Have it load tested anyway. Silly to waste time with anything else if the battery is trashed.

I'll charge it up tonight and see if I can get it load tested tomorrow

Charge that battery up and hope that it takes a charge, then if it does try to keep it charged otherwise you will damage a $200 battery. They don't come back 100% after dropping that low and if it happens to many times you will need a new battery.

How to determine what is draining you battery is one of the hardest things to troubleshoot. You must have a digital meter or an amp meter to even start, but it is a tedius process of elimination.

I start by connecting the amp meter and then start disconnecting things until it goes away. Start with the aftermarket stuff, alarm, stereo, amp, lights, etc. If it is factory equipment causing it that is much more difficult. With the amp meter in place you can start pulling fuses one by one.

Good luck

Bump

I honestly would never pay $200 for a battery. You would have to do whats called a current draw test. You need a digital multimeter with amps and a lot of patience. You would take amd remove the negative terminal from the battery. Connect one lead of the multimeter to the negative battery post and the other lead to the negative terminal ( putting the meter in series) turn your meter on to the amps setting. Close all the doors, turn off the key any any other loads like lights and etc. dont forget about the underhood light. Wait 30 minutes and see where your meter reads anything under .05 is acceptable but .01 or 0 is ideal. Anything above that will kill a battery. If it is reading high then you start pulling fuses 1 at a time until it reads zero. Then find the wiring diagram for the fuse you pulled thats made the meter read 0 and go to each of the components that the fuse controls put the fuse back in and start unplugging each component 1 at time until it reads 0 when you have then found the component that is causing your draw. If you have and aftermarket alarm system I would start there first. Also with 5 volts sounds like you have a dead cell. Optima batteries are not as reliable as everybody believes.

optimas made in the last few years are notorious for sucking major balls. you probably got a bad one. i only buy Deka brand batteries.

Remove wires from battery
attach multimeter to battery wires in resistance mode.
remove fuses one by one and watch if resistance changes

Wow car5car so descriptive. You dont use resistance. Resistance=ohms which is how much a component opposes electrical flow. When checking for draws we are no checking for the opposition of electrical flow we are checking the rate a which current is being used (amps) so we need to setup our meter to measure amps or milliamps. Some meters will only have the amp setting with autoranging. Others will have amps and milliamps. The meter will need to be connected in series with the battery.

Attaching an ohmmeter to a power source means a blown meter or meter fuse.