My 2002 Fx4. Last Friday it cranked really slow but started. Let it run a few minutes and shut it off. Cranked normal and ran fine and started fine the rest of the day. Today I tested for parasitic draw with hood lamp pulled and I get 0.22...which is good. But the meter jumps to 1.95 to start but within 10 seconds settles in at 0.22-0.24 range. I pulled the main wire to the alternator and tested again...same results. I pulled the 3 month old 1000 amp battery and left it on the bench all day and it has stayed at 12.70...no drop. I put my Mustang battery in it this morning and it had 12.3 volt. It has been in the basement all winter. Drove 20 miles came back and checked...had about 12.35 volts. Tonight I just checked and it was down to 12.0 volts but truck started fine. Charging voltage at idle is 14.7. It shows no parasitic draw that I can see on my meter......3 month old battery seems to hold a charge on its own.....maybe take battery back and have them test it???? The last battery lasted 1.5 years and was bad and got this one free on warranty.....Wal-Mart battery....Any ideas....parasitic draw seem within limits?

Temps today in the teens, with low last night of 6 above. Never any issues all winter and much, much colder.

 

Just realized the initial 5-10 second spike in amps when testing was probably "wake up" voltage. Now I wonder if maybe the starter was drawning too much that one time? I didn't test the voltage after it happened.....hmmmmm.

 

Parasitic draw should be under 50mA after modules go to sleep.

 

Yep....I am at 22 mA consistently so unless something was stuck that one night I have to assume it is either battery related or starter draw. I did pull the hood bulb just for giggles. I don't know if that is part of the battery saver circuit or not if it should stay on. Thanks for the reply.

 

note that 22 ma is .022 amps........... .22 is 220 ma... just a question ?

 

LOL...This ALWAYs comes up....expressing the values. All I know is there is 1000 milliamps in 1 amp. I am drawing 22 mA....almost 25% of just 1 milliamp. Everything I have read says 20-50 milliamps is OK. Maybe I am expressing it wrong....dunno'. I compared the readings to my other truck with no issues and they were almost identical.

 

LOL. Actually, that is 22X (or 2200%) of 1 mA or .022 of 1 A.

Anyway, 22 mA is a good value.


Yeah, stop buying Walmart batteries!. My old 97 had the same problem that was solved by finally buying a new battery at O'reilly's after three duds from Walmart in three years.