Tow haul mode and battery charging
#1
Senior Member
Thread Starter
Tow haul mode and battery charging
I just read a post on a different forum. Guy claimed that the GM trucks increase the electric power going to a trailer when the truck is put in tow/haul mode. Supposedly helps charge the trailer batteries. Two questions - is this true? Does Ford do the same with the F series?
#2
Senior Member
Absolute hogwash.
#3
Actually on the 2015+ it won't even charge the battery until you name the trailer (in the Productivity Screen) and step on the brakes the first time. I assume that circuit isn't hot on a trailer without a battery.
#4
Isn't the amount of current limited by the wire between the battery and the trailer? Not sure how you would just increase this by pushing a button? Sounds like a dealer invented feature to me.
#5
Senior Member
I just read a post on a different forum. Guy claimed that the GM trucks increase the electric power going to a trailer when the truck is put in tow/haul mode. Supposedly helps charge the trailer batteries. Two questions - is this true? Does Ford do the same with the F series?
Before you say hogwash, google GM Regulated Voltage Control.
I don't know what the all the Ford parameters are, but it has a similar system on it. I would not be surprise if tow mode sets the voltage higher but running the headlights will. Ford calls theirs smart charge
The following users liked this post:
SailorSam20500 (02-17-2017)
#6
Senior Member
OK, I was thinking he meant they were regulating trailer charge line voltage separately from the vehicle system voltage.
#7
The factory charge line on my 2015 F-150 is 18 gauge wire. I was told by Ford that its intent was to only maintain the trailer battery charge while driving. Its been a while since I did all of the the measuring but recall it can only handle an amp or two of current before the voltage starts dropping off pretty quickly.
Trending Topics
#9
Senior Member
I've watched the voltage on my Scanguage go from 13.4 to 14.3.
#10
Senior Member
Yes, the computer commands the alternator to adjust the voltage to different levels depending on the state of charge of the battery (Target is between 80-90%) and electrical needs. The battery charges best at 13.5 volts and 15.5 if it has a AGM battery in it as mine does. 13.5 and 14.5 on a regular flooded battery. Below 13.5 the battery won't charge much if it is above 80% charged.
If electrical needs are low, the battery is charged, the truck is on level ground and at a moderate speed, you may see it fall to near 12V to save gas. The voltage settings are 11.8 to 15.5 depending on conditions.
If electrical needs are low, the battery is charged, the truck is on level ground and at a moderate speed, you may see it fall to near 12V to save gas. The voltage settings are 11.8 to 15.5 depending on conditions.