Hey everybody! I hope you're all doing good .

I've got a battery drain issue that I can't seem to pin down .

I just checked for parasitic draw , and I measured around 200 Milliamps (.2 plus amps) that i am losing when the truck is sitting there everything off .

ive got the system off to save battery message. I fully charged battery and let sit 8 plus hours to reset battery charge levels in the computer .

I read there's quite a few folks who get this message and did the manual reset trick (the brights flash brake pedal etc) and it does not work on my truck surprisingly!

At any rate I have an optima redtop . I have never had it changed to AGM battery in a tuner or anything .

When I got the message I checked voltage i beleive i was 12.2-12.4. Charged on battery tender to 12.8 volts. Drove about 10 miles half at highway speed and at destination still had message and then was at 12.4 volts !! Lost .4.

Threw new battery in optima redtop as i assumed it was the battery. Had the battery tested and it was still good . Now I've got a new redtop for my old f250 haha !

Any ideas appreciated !

I pulled all fuses in engine bay and no fuse lowered the amp drain .

Truck is a 2011 f150 lariat supercrew shortbed . 4x4 ecoboost .

On a side note when battery is hooked back up after disconnect the cd cycles through all 10 spaces it sounds like .

 

several things... first is to charge the battery, you have to put the GROUND cable on the engine, not the battery.. The Battery Management System is monitoring the charge thru a block on the ground cable several inches from the battery.... Second, you have to wait 15 minutes or so after connecting the amp meter to see if the parisite draw drops.. There is some timer on the system...

What you might want to do is UNPLUG the BMS ( battery management system) for a few days and see if that fixes you problem..

 

look at the drawing of the plug on Post #18 on this link...

https://www.ford-trucks.com/forums/1...nt-system.html

 

The "go to sleep" timer is about 40 minutes. If you measure current draw before then, you're guaranteed to go down a rabbit hole.

 

Thank you for the advice, ill unplug the BMS for a few days and see how it does . I see the picture on that thread very helpful

i went negative and positive terminal first time I charged in vehicle. Then I read about the ground wire and the last charge was through the ground wire instead of negative terminal .

Okay gotcha ! So i need to plug in my amp meter and wait 15-40 minutes. Will do for next time .

 

40 minutes minimum. Period.

Anything less - rabbit hole.

 

Gotcha! I'll get the meter hooked up and wait 40 minutes . I might even stretch it to 41 !

I about blew my meters fuse up when I opened the door the other day . 8 some amps went through meter when the lights came on and it's only good for 10 haha

 

Well waited 40 plus minutes and found out my draw is only 12.8 milliamps ! Thats nothing!

So disconnect BMS for a few days and then hook BMS back up ?

Can anyone see any issues with the system computer not updated to the fact that I have an AGM battery right now instead of stock lead acid?

 

I disconnected my BMS sensor 9 years ago due to this issue. Not a problem since.

 

I like the sound of that !!

Okay I'll disconnect and see what happens.

 

Unplug #10 as shown in this pic. DO NOT unplug anything else.

 

Yep that's what I did just drove it truck ran great zero issues !! Thank you so much everyone have a great weekend