Key-off battery drain

[zzb3886]

The battery of my 00XLT died just after being parked for a day (temperature in 40's). It was driven for two hours yesterday, after started by some weak cranking. Today the cranking was much weaker with clicking. I pulled the battery and measured the key-off battery drain current to see if there is any parasitic draining. The current went up to 900mA for about three second after connection, and then stayed at 200mA. :roll: Is this current too large?

Don't have a battery charger. Now I'm hooking up two computer power supplies to charge it...

 

[hworksinc]

There are a couple of threads about this. 200-300mA is a normal battery draw when everything is off, doors closed/locked. You're basically powering PATS/RAP, and radio/computer memory.

You're battery is most likely at fault (maybe the charging system). Take the battery somewhere and have it tested, but I bet that's the problem. If not, check the alternator and the major wiring.

 

[dynamite196]

Have the battery load tested, if that checks out, you can test the alternator simply by starting the engine and testing voltage at the battery, it should be ~13.5 volts. If that all checks out, make sure there aren't any loose connections on the starter wiring and check the resistance on those wires (should be about 0 ohms). Finally, if everything so far is in good working order, most likely the starter is just about dead.

 

[scucci]

200-500ma. is specified for the 45 minutes before the battery saver kicks in. Then the max is 50 ma. My 98 draws 225 until the battery saver kicks in, 17 ma after 45 minutes.

 

[foodman392003]

Battery drain

Motorcraft batterys short internally. It can look like all kinds of things are bad. Get the battery checked first. If it is good,then disconnect the neg on the battery and put a test light between the battery post and cable. There should be a low light glowing light for raido and cumputer. If it is bright then go to your fuses and pull till the light dims or goes out. That will give you a idea where to look for the draw.

 

[zzb3886]

Thanks for all the replies. I did a long parasitic drain test. Came back a hour later, the current reading was 15mA. So that is good. I took the battery to sears (diehard battery), they tested and said it was good. But I found one cell was significantly different from other five cells using a hydrometer. I'm going to replace the battery anyway because I don't trust it.