mjs3350

I just bought a 2016 reg cab long box f150 to use as an all purpose vehicle. I'm adding and A.R.E. cap and plan to turn the back into a simple camper, and want to run an auxiliary battery for camping comforts (charging phone, laptop, running fan, lighting, etc) without risking a dead primary battery. I was planning on mounting the aux battery on the frame rail and running a solenoid to charge it while the truck is running, but isolate the aux battery from the main battery when the truck was off. However, after doing some research, it looks like the battery management system makes this a little more complicated, and was wondering if anyone has successfully done this on the current gen f150s. I'd really like to avoid charging off the trailer harness, it's just too slow to be practical for my use. Thanks ahead of time for any help!

LoranceN

I've been scouring forum threads and manuals also looking for information on how best to add a dual battery to my new 2017 supercrew. I had just created an account here when I saw your post on the same topic!

Here is what I've managed to piece together so far:

I've found a little bit of information about the BMS, in that Ford recommends all aftermarket negative grounds go to frame so that the hall effect sensor off the battery negative terminal can account for those loads.

Information here:
https://www.fleet.ford.com/truckbbas/non-html/Q-231.pdf


I also saw a thread where someone mentioned disconnecting the sensors, resulting in a code being thrown, but no check engine light or messages resulting, basically has the effect of kicking the truck back to a default, non managed configuration. If this is true, I'd be fine with loosing that management functionally as long as no other systems are disabled or load shedded.

My power loads (and truck build) are going to be focused around volunteering for search and rescue, so a winch, VHF radios, and lots of lighting definitely make me want to have an aux battery to run these additional loads from, without risking my primary battery.

Cheers!

-Nathan

mjs3350

Thanks for the info! I'm hoping to find a way to make it work without bypassing the BMS, although my truck has minimal bells a whistles so I'm not sure how useful the BMS actually is for me.

Livnitup

The BMS can be disabled with FORScan if you end up deciding to do it.

LoranceN

That's great to know Livnitup, I just got the Bluetooth adapter, and registered for the software, I'll give this a look.

stormsearch

Both are true. Basically what we are doing is preventing the truck to either not know (by disconnecting BMS sensor) or not use the battery state of charge value (FORScan disable); vehicle will default to the standard charge mode. For ultra performance geeks, this will hurt your 1/4 mile times as the BMS does reduce alternator engine load under high engine acceleration and will affect Start Stop functionality if applicable for your truck. It will affect fuel mileage but nothing each individual will find detectable.

It is also worth noting that for S/S vehicles it is setup for the original OEM battery. If a different type of battery is used it will also affect the vehicle functionality to accurately control load shedding, S/S, and other BMS functions.

mjs3350

Thanks all. Looks like I'll be diving into Forscan earlier than I'd anticipated. I was a little nervous but the sticky helped make sense of it. I'll just need to do some digging to find exactly what to change in Forscan to disable BMS. I'd rather do it that was so I can reverse it for any warranty work that might come up.

Livnitup

BdyCM
726-04-01 xxx2 xxxx xxxx Battery Monitoring System is Enabled
726-04-01 xxx0 xxxx xxxx Battery Monitoring System is Disabled

Jim10517

So, I shouldn't connect the negative lead for auxiliary lights to the negative terminal block on the battery?

mjs3350

Many thanks!