Just heard from the Dealership. There was and excessive parasitic drain. They didn't say exactly what it was but they found that the BCM had the factory firmware loaded so they flashed it with the latest update. The parasitic drain at rest fell to 19ma which is well within specs.

This fix is per the service note and is not in a published service bulletin as of yet. If you have a similar problem with your 2013/2014 F150 then make sure you mention that there is a service note (not service bulletin) about it and they should read it when trouble shooting and apply if appropriate.

Electrical Gremlins come in various forms so I can't say that your problem will be fixed using this info but it's definitely something you want to mention or it may be overlooked like it was with mine.

 

funny my '14 went in for that problem AND a power steering power failure; they could never find the problem so they replaced the battery but I already traded that rig in today!

 

Yes, it is a recognized but not a widely publicized issue. In my case, my service Rep at the dealership was key in getting to the current resolution. We've become friendly over the years, my lifted 2008 F350 SD Diesel was in the shop every 5,000 mi for one thing or another. Every time it went in it stayed at least overnight. Ford made sure I always had a rental vehicle and it never cost me a dime except the cost of the inconvenience. When I drove Chevy's I never got that kind of service but to be fair, I also didn't have as many problems.

They say that the overnight major discharge problem is fixed but I still need to drive it more often or I will experience frequent low battery warnings. Alternatively, they suggested that I either disconnect the battery neg or put a battery tender on it when I don't plan to use it for more than a few days. That's a work around at best so I'm hoping for a service bulletin with a permanent solution or a recall in the near future. In the mean time, I guess I'm just going to have to go fishing more often. My new catch phrase is "Need an excuse to go fishing more often, buy a Ford F150".

 

Diesels have two batteries, that doesn't mean there is parasitic drain from the batteries, but with all the electronic gizmos they're putting into vehicles they almost need a separate battery just to run all the electronics separately from the car battery. and by having two separate electrical systems they'd need two master fuse boxes, etc Cool thing is Lithium Ion is small (and expensive) but LiIon will last longer when not in use which is also nice.

I hope my '16 doesn't have that issue

 

Knock on wood, but my '13 doesn't have that problem............. Since last October, Ive put 400 miles on it. started it 2 weeks ago and drove it 30 miles. (I keep it in the garage)

 

The problem stems from them using rudamentary keep-alive technologies. While they make life easier for us that want instant gratification in our vehicles, they do have the inherent drawback of needing a constant power source. There are better solutions and it appears that Ford may be using those in it's 2015 and up vehicles.

 

Do you know what they've done in the '15+ to fix that? I noticed that my truck has wifi... LOL!!!! Like... seriously? Oh and I can't connect to my home wifi the range is too short since I live at an apartment I need to literally be parked in front of my apartment for it to pick up my wifi and since I don't pay for parking... well that's difficult but I don't need wifi every day either strangely enough it won't pick up our WAN wifi (we have an apartment-wide WAN provided by Xfinity in addition to our personal wifi that we pay for).

Glad I'm only here for 2-3 years... moving on after that! (probably no wifi then :P but good thing I have the Verizon jetpack, I can always use that, and if it comes down to it I can do that at my apartment too).

 

Don't know what they did other than add more features at an obviously lower battery cost.

 

I noticed there is an inverter installed on mine as well; so maybe that has to do with the lower battery cost?

 

I can think of a number of reason why an inverter might be present but can't tell you definitively what Ford is using it for. If it's not an auxiliary 120v access point then it's likely to provide a -5v that can be used for various things.

 

the 120v would be one of the reasons since there's two standard household 3 prong plugs; not sure what the wattage is on those inverters but can't be more than 500W since its not very big and usually the 2,000W inverters are pretty big.

idk about the 4 12v cigarette lighter outlets since its 12v I don't think it would go through the intverter; but I'm sure the inverter is also handling some of the power for some of the accessories in addition to the 120v three prong outlets maybe?

 

Diesels technically have one battery (in two cases) from an electrical standpoint.

Your idea is a good one. Maybe a small motorcycle type battery, LI or AGM to keep the modules powered up and memory saved, security, PATS, remote etc, but the main batteries physically disconnected and not subject to any drain. It would be pretty trivial to set it up.

 

well I discovered the big difference between '14 and '15/'16 (I can't say for sure about '15 since I have not owned a '15) but as soon as you close the door and the lights go off... all the power is turned off, that means all 12v and inverter power isn't active... I think that was one of the main battery drain in the '14 but I loved having always on power to charge my phone or tablet; can't do that on the '16 unless you're in full accessory mode which powers on EVERYTHING (your dash, your radio, the inverter, the 12v system, interior AND exterior lighting! humph!

But if I wanted an always on 12v that has cigarette lighter and/or usb I'd have to hardwire it directly to the battery... but the truck has so much already there's no room! LOL

 

That would certainly solve it and it prompted me to see just what effect the BCM firmware update had. The big change I see is that the second I hit the door lock it shuts off everything that's not essential. I didn't have my phone with me but I suspect the USB ports would still be active because they do not draw any current if not in use.

I did check the voltage and charge percentage again this morning and it was 12.4v @ 70% when tested from positive to a body ground. This measurement would include any voltage drop due to active devices in the circuit. I suspect that the disconnected battery would read 12.5 to 12.6 and charge percentage would be in the 90's. That's normal and I now believe that the BCM firmware upgrade did fix the problem.

 

ah in my case the '16 everything shuts off, including USB so there's no charging capabilities at all when you lock the truck. But it couldn't hurt to have USB active though... oh wells...

I should look into seeing if I can get a self contained battery+inverter that is small enough to fit in the center console