Charging Trailer batteries?

[2tracks]

I have a 2020 Ford tow vehicle. My TT has 2 deep cycle batteries and a WFCO 8955PEC that charges the batteries when on shore power. Does the tow vehicle charge them when on the road?

[acadianbob]

Yes, but it will be a small charge. If you have a 2 battery system and it is discharged, the tow vehicle is not going to do too much. It will probably only provide 3 to 5 amps. It would take many hours, at that rate, to charge your batteries.

[2tracks]

New to RV life. I also have a Xantrex Freedom X inverter on board to power the residential refrigerator the inverter has a charging function so I'm presuming that charges them while in tow? Just trying to get my head around how these things work. My inverter stopped working and I'll be replacing it.

[ependydad]

Originally Posted by 2tracks

New to RV life. I also have a Xantrex Freedom X inverter on board to power the residential refrigerator the inverter has a charging function so I'm presuming that charges them while in tow? Just trying to get my head around how these things work. My inverter stopped working and I'll be replacing it.

No, the charging function from inverters requires that you be plugged into shore power.

And, given the trickle charge that acadianbob mentioned, you're almost definitely discharging the batteries while the inverter is powering the fridge.

You might consider a proper battery monitor so you can really see what's going on with your batteries. There are a lot of options, I happen to like the Victron BMV:
https://learntorv.com/victron-battery-monitor/

[NoviBill]

I am not sure on the Fords, but GM vehicles by default have the charging circuit disconnected (just need to hook up the wire to the terminal). You can verify if the vehicle is charging the trailer battery in many ways, one of the simple ones is hook up a volt meter to the battery in the trailer with the trailer disconnected. You should see between 12.5-13 volts for a good battery. Next plug into the tow vehicle and start the vehicle, re-measure the voltage you should see it jump to 13.5-15. In many vehicles the Tow/Haul switch will boost the voltage output of the alternator helping charge batteries. So turn on tow/haul and measure again if you see the voltage go up tow/haul will charge your batteries faster.

*If you don't know how to use a voltage meter, read up on safety before doing this. 12 volts can do a lot of damage - drop a wrench across the terminals and it will turn orange, red, white and fall as a pool of molten steel into the top of the battery. Please don't repeat my errors.


The reason (I have heard) for it being disconnected by default is 30amp 12 volt wire running from the hood to the trailer hitch is a small but real risk (shorts, sparks etc) and most people do not tow. *I work for GM, but this is not my area of expertise so my knowledge based on public info and does not represent GM

[PhilFromMaine]

I have read that your 7 pin, if it is "hot" will maintain charge to the TT battery. If you have deeply discharged batteries, or lithium batteries, you need a DC-DC charger.

[2tracks]

I have to replace the inverter so I guess I won't need one with a charging function since the WFCO 5955PEC power center does that when on shore.
Mt trailer does have a simple battery monitor and the batteries are pretty much always fully charged.

[bikendan]

Originally Posted by 2tracks

I have a 2020 Ford tow vehicle. My TT has 2 deep cycle batteries and a WFCO 8955PEC that charges the batteries when on shore power. Does the tow vehicle charge them when on the road?

My 2014 F150 Ecoboost provides a trickle charge while towing. But you should always check the charging pin in the umbilical cord.

[doanshop]

You need to remember it takes 14 hours to charge flooded batteries 100%. But your tow Vehicle will charge some if setup that way.

[Scrapper]

Originally Posted by 2tracks

New to RV life. I also have a Xantrex Freedom X inverter on board to power the residential refrigerator the inverter has a charging function so I'm presuming that charges them while in tow? Just trying to get my head around how these things work. My inverter stopped working and I'll be replacing it.

Since your new to RV life you should check out the following sticky post;
'New to RV's helpful hints’ by wmtire.

Originally Posted by 2tracks

I have to replace the inverter so I guess I won't need one with a charging function since the WFCO 5955PEC power center does that when on shore.
Mt trailer does have a simple battery monitor and the batteries are pretty much always fully charged.

If your calling the lights on the panel a battery monitor, you are gravely mistaken. Those lights will show full charge only while plugged into shore or generator power because the WFCO 5955PEC power center is on float charge. If you disconnect from shore or generator power that full indicator will go out.