04 Taurus battery dying when not in use

[Opr2135]

Hi guys! Newcomer here in need of help!

My problem is that my battery in my car has spontaneously died on me twice within a month now, when the car is not in use. The times I started up the car previous to discovering my battery died seemed perfectly fine, it starts right up, but I'll leave the car in my driveway for a day or two and go back, and the battery doesn't even have enough juice to turn the motor over. I am absolutely, 100% positive I'm not accidentally leaving the headlights on or anything like that.

I've had the car for a few months now and this problem only appeared within this last month. The only different thing that I have done with the car in this 1 month problem period is use the car's stock CD player instead of listening to the radio (if it matters, the car is equipped with the factory 6 disc changer, but I don't have the cartridge for the other 5 discs so I only use the slot loader).

The car has ~60k miles on it, and I replaced the first dead battery with a brand new one figuring it may just be time for a new one after so many miles. However, today I went to start my car up and I had the same problem, no juice. The new battery is still under warrantee so i'm not too concerned about that, but is there a problem with my car or did I just win the cruddy battery lotto here? If I didn't include enough information please let me know what you need to identify (or at least narrow down) the problem. Help is GREATLY appreciated, thanks in advance!

[consultIII]

Did the no start occur the day after the battery replacement or was the new battery ok for a while?

fully charge your battery and then check for parasitic draw.

Its unlikely that 2 batteries are bad but it is possible. New batteries aren't fully charged and may have not been fully charged by just driving.

slow charge the battery for 8hrs. Conductance test the battery if a jobber in your area provides this service for free...maybe where you bought it. This rules out the battery.

If battery ok, check for parasitic draw. Any draw over 50 miliamps is considered excessive.

If draw ok, check alternator output.

[Opr2135]

Thanks for replying! The new battery worked perfectly for about a week.

I don't actually own a battery charger so I will take it back to the store I got it from to have it tested and charged tomorrow morning for free (its just about closing time right now).

I don't expect its the alternator because when the car works, everything works great (strong motor, bright lights, loud music), plus the car isn't even on when the battery is dying, so if the battery isn't the problem I'm expecting some sort of parasitic draw. Of course I'm no expert so feel free to correct me here.

Since I have to wait to test the battery, how should I test for (and locate) a parasitic draw?

[inafogg]

with any volt meter ,test light ect.. put in series with battery WITH NEGATIVE BATTERY CABLE DISCONNECTED(neg from meter to neg post on battery & positive ON METER to NEGATIVE BATTERY CABLE) no more than 1/2v- 1v
Good Luck

[consultIII]

use a dvom set to amps as you want to measure current draw. You want a reading 50 milliamps or less after all the modules power down; which could take as long as 20min on some vehicles. Anything higher will drain the battery.

An inductive amp clamp is best as it won't wake up all the modules which is what will happen when you disconnect then reconnect the negative battery terminal.

using a dvom set to amps (make sure the red lead is in the amp terminal of your dvom), disconnect the negative battery terminal and connect the black lead of your dvom to the battery post and the red lead of the dvom to the negative battery cable terminal. Make sure everything is off as a key on or open door will draw enough to blow your meter fuse.

As you make the final connection all the modules will wake up and create a draw; this is normal. The modules should power down and go to sleep in maybe 5min. This is the reading you want.

Post your results and if needed will isolate where the draw is coming from

[shorod]

When the car gives the appearance of a dead battery do you get any sound from under the hood such as a single click of a relay or a rapid clicking? What doe the indicators in the dash do? Do they all come on and perform a bulb test? With the key in the run position does the radio work? If you try starting the car with the driver's door open what do the interior lights do when trying to start? Do they change much in brightness or go out completely? Have you checked the condition of the battery cable connection to the main power distribution box? Before checking the current draw on the battery I'd suggest hanging the multimeter across the battery and monitor the battery voltage with the key off, with the key in Run, and finally while the key is held to the Start position. If the battery is around 11V or higher in Run and doesn't drop below 10V when trying to start the car, the issue would seem to be something other than the battery, more likely a bad connection somewhere. If you need to move on to measure current, be sure to reposition the meter leads as mentioned by consultII above.

If using a current meter in series, use the highest current scale on your meter (probably 10A or 20A). Even though you are looking for something less than 100mA, the inrush current may be several amps. Using the mA setting of your meter will likely blow the fuse as soon as it's placed in series with the battery. It may take 45 minutes or better before all the modules in your 2004 go in to sleep mode, 5 minutes certainly won't be enough and 20 minutes may not be.

-Rod

[inafogg]

ok Rod i understand but can 1 install meter in series the ''old school'' way
just have to wait for modules to go to bed????
Thanks mike

[Opr2135]

Ok I'm getting ready to go out and get my battery tested, but here's some answers for Rod-

Yesterday (when I discovered the dead battery for the second time) I got rapid clicking and Some lights on in the dash (I don't remember which ones, just that some lit up). I went out today to see exactly which lights lit up and I did not get ANY clicking, and absolutely no lights. The radio display doesn't even light up with the time, does not work. Today with door open while starting it doesn't do anything different than door closed because NOTHING works.

I have not checked the condition of the battery cable connection the the main power distribution box.

I'm gonna go get my battery tested and charged then start fiddling with the multimeter and get some more answers here right now.

[serge_saati]

Testing the parasitic drain is very simple.

1) Close the doors and wait until the indoor lights turn off.
2) Disconnect positive terminal of the battery.
3) Put the + plug of the multimeter to the 10A fused input of the meter.
5) Select the knob to DC amp or 10 DC amps (straignt line symbol)
4) Plug the + wire of the multimeter to the + of battery and the - of the meter to the red positive cable.
6) read the value
7) reconnect the terminal.

Next day, test also battery voltage. You should have at least 12.2V.

[Opr2135]

Update- I took the battery in to have it tested and they told me something was internally wrong with the battery and I got a free replacement. They still weren't sure if it was caused by the car or the battery, and they told me to bring the car back when I put the new battery in to test the alternator. Do you guys think I should still test for a parasitic draw after I test the alternator or just call it good?

Also, you guys are awesome! Thank you so much for the advice!

[serge_saati]

Yes do the test. It may save your 3rd battery.

[Opr2135]

Alright the alternator tested fine, the guy said there wasn't any codes being thrown or anything else. I'll work on testing for a draw (if I'm understanding these instructions correctly) right now and post back on how it ends up.

[Opr2135]

Okay this took way too long for me to figure out, but my multimeter is a cheap piece of junk and doesn't have a 10A fuse capacity (I didn't exactly understand step 3 of serge's neat instructions until now)... I went to test my battery and blew the multimeter fuse twice. Right now I'm working on borrowing a better multimeter from somebody but that could take a day or two to make happen.

At this point, the blown fuses tell us there is indeed a draw of some sort and just can't measure it, right? Should I reconnect the battery terminal just to see what happens (I don't have anywhere important to drive anytime soon, and the newest battery is still covered under warrantee)?

[serge_saati]

If the fuse blew, it means that you have a very important draw.

In your meter, it should writed the current capacity. I never seen a digital multimeter with less than 10A of capacity.

[Opr2135]

This one is analog, uses a 0.5A fuse