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As my driving patterns are predominately very short trips over extended periods of time (sometimes months) I feel as though routine battery charging on my 2018 could be beneficial. My prior 2000 F150 formed the foundation of this belief as it required periodic charging. The experiences of others on the '15+ forum seem to validate the concept. Therefore I have installed a quick connect harness to facilitate a permanent, more secure method to accomplish charging.
Everything I read about battery charging on vehicles with the battery management system suggests that the negative connection of the charger should not be made directly to the negative battery terminal but should be made to a ground point on the body/frame in order for the charging current to pass through the BMS so it can properly perform whatever functions it performs (or something like that).
So I question whether my ground point connection is sufficient to accomplish the proper charging loop. That connection is indicated as position #2 in the attached photo. Position #2 is also used as the ground point for something else, but I cannot ascertain what that might be. (Position #1, the easiest place to put the ground, is directly connected to the battery so I presume the proper charging loop will not be accomplished there.)
Does anyone know whether position #2 is directly connected to the negative battery terminal or may pose some other impediment of which I am unaware?
To charge or jump start the vehicle, connect the positive cable to the battery positive post.It is preferred to connect the negative cable to a vehicle ground and not the battery negative terminal. Connecting directly to the negative battery post can have an adverse effect on the Electrical Energy Management system. For a good connection point, follow the cable from the battery negative post to the vehicle body connection (typically on the shock tower sheet metal) and connect there.
If the battery is jump-started or charged, the BCM must recalibrate the battery state of charge. Engine off load shedding may occur if the vehicle is operated before the BCM calibrates the new battery state of charge.
NOTICE: DO NOT reset the battery monitoring system using the diagnostic scan tool. This reset is reserved for new battery installation. Resetting the battery monitoring system will clear the learned battery data, the battery time in service, and will affect the aging algorithm parameters, which have been learned since the installation of the battery.
Some years ago I installed on my 2013 a Battery Tender Plus. I followed Battery Tender's instructions and connected the cables to the terminals, and have had zero issues. I suspect this is because the Battery Tender Plus keeps it from ever getting low, and because it sits for days, well over 8 hours, between drives.
With smart battery chargers, it's always better to connect them directly to the battery. Extra resistance using chassis ground can lead to slight over or undercharging, and sometimes charging errors. The reason Ford (and all other manufacturers, I bet) says it's 'preferred' to connect pigtails to ground is because if you use more than 5 amps, you could damage electronic components. So when you jump the battery, or use a high-amp charger, you absolutely have to ground the negative post on the discharged battery, rather than using the battery terminal. So they just want to play it safe. I installed a pigtail directly to the battery since day 1, and have been charging it with Optimate6 with zero issues. Finally, I like that BMS limits charging when your battery is fully charged, when engine is in high demand it cuts out charging, and when battery is low it prevents it from further discharging and leaving owner stranded. But I don't like its aging algorithm, since a battery that is regularly charged lasts a lot longer than a neglected one. But will keep an eye how it behaves as the truck ages. I like to replace my batteries every 5 years max, so it might not be an issue at all. But would like to read how the system triggers a relearning of the battery state of charge after charging the battery, other than resetting the system when you install a new battery. I don't follow some algorithms, like the oil 'life', for instance. But the battery one is really good, and that's why I didn't want to disable it to get rid of auto start/stop, which is exactly the way FORScan disables *** (by disabling BMS, since *** cannot be disabled alone, since it's an ECU function).
... For a good connection point, follow the cable from the battery negative post to the vehicle body connection (typically on the shock tower sheet metal) and connect there. ....
Does that mean that location #1 in my picture is an appropriate place to connect the negative terminal or the battery charger? (Location #1 comes directly from the negative post of the battery.)
Mine is charging as I write this - since I have a canopy with a 12v power point installed near the door, I charge through that, which is fed through the BMS pickup. Has worked fine in this and my previous F-150.
Does that mean that location #1 in my picture is an appropriate place to connect the negative terminal or the battery charger? (Location #1 comes directly from the negative post of the battery.)
11-18-2018, 12:39 PM
Battery charging with BMS
