TT battery charging question?

[joelyn]

just bought our first TT and was wondering if the TT battery in the front by the propane tanks gets charged while towing it behind our truck when using the 7 pin trailer electric cord that provides electric to ur lights etc while driving. Does it also charge your battery?
thanks
joe

[BigSkyTrailer_G]

Unless you're driving for 48 hours between campsites, your battery charge from the tow Veh will be quite ineffective - Trickle charge from alternator can't hurt, but I wouldn't rely on it as my "batt recharging strategy" it'll ultimately kill your batt's bounce-back capacity. True deep cycle rv batteries thrive on a good 48-hour / 3-stage recharging.

[Lance72]

I installed a Marinco 701 battery disconnect switch. hardest part was finding a place to make the new 6 AWG cables with ring lugs I needed. i did find a blade disconnect that connected directly to the battery terminal. Battery Doctor® Knife Switch for Top Post Batteries w/ Stud - 20148

[itguy08]

WyoTraveler wrote:
If you don't have a multimeter buy the $6 one at Harbor Freight. The cheapo meter is a very good meter to learn with. If you use a wrong setting and zap the meter not much is lost.

Keep an eye out for Harbor Freight coupons. They have a Free with purchase of that $6 meter. It's not the best quality but great for in the RV. And if it dies soon, you were out $0 or $6.

[westend]

One thing you can do to extend the life of your battery is to install a disconnect switch close to the battery. Make sure the breakaway brake system and electric jack are not wired through the switch. You want them powered continuously. They don't have any parasitic draw from the battery but other items inside your TT do. The disconnect switch is used for storage situations.

[joelyn]

BubbaChris wrote:
For the OP - How much charge are you looking to get from the TV?

Are you looking to make up for night(s) of boondocking/dry camping? Or just to help run


the 12V system in the TT in-between FHU stops?

just looking for some type of trickle charge to keep the batteries from dying out, not much

[BubbaChris]

For the OP - How much charge are you looking to get from the TV?

Are you looking to make up for night(s) of boondocking/dry camping? Or just to help run the 12V system in the TT in-between FHU stops?

[Ron3rd]

joelyn wrote:

mbopp wrote:
If you post what your tow vehicle is, it'll help. Manufacturers implement the charge line in different ways. Some are always hot, some use a relay, and most need you to enable the charge line by adding a fuse and / or relay, or putting a wire terminal on a fuseblock post.

its a 2012 dodge ram 1500 crew cab w/ 5.7 hemi

Yes, your Ram will charge the battery while towing, provided that circuit is activated with a fuse or breaker as noted above

[joelyn]

mbopp wrote:
If you post what your tow vehicle is, it'll help. Manufacturers implement the charge line in different ways. Some are always hot, some use a relay, and most need you to enable the charge line by adding a fuse and / or relay, or putting a wire terminal on a fuseblock post.

its a 2012 dodge ram 1500 crew cab w/ 5.7 hemi

[WyoTraveler]

It is good to know if that line is hot all the time. Ford only charges with vehicle running. Some vehicles that line is hot all the time. If you stop over night and leave everything connected you don't want to end up with a dead vehicle battery in the morning. If you don't have a multimeter buy the $6 one at Harbor Freight. The cheapo meter is a very good meter to learn with. If you use a wrong setting and zap the meter not much is lost.

[mbopp]

If you post what your tow vehicle is, it'll help. Manufacturers implement the charge line in different ways. Some are always hot, some use a relay, and most need you to enable the charge line by adding a fuse and / or relay, or putting a wire terminal on a fuseblock post.

[SoundGuy]

A pic is worth a thousand words ... 😉

[RoyB]

It depends.... Most newer trucks provide the TRAILER TOW FUSE and RELAY in a plastic zip bag laying in the glove box which need to be installed in the main fuse panel first. You will have to check your service manual and find the slots where the FUSE and RELAY goes. I think mine was marked TRAILER TOW or something like that in the diagram pictorial of the fuse panel that is mounted on top of the radiator in my 2010 F150 truck.

This allows the BATTERY in the trailer to be charged from the truck side when you plug in the 7-way trailer cable in when the truck ignition key is turned ON...

You can test this by using a MULTIMETER across the battery terminals which will read 12.6-7VDC if the trailer battery is fully charged. After hooking up the 7-way CABLE and starting your truck you should see the DC VOLTAGE across the battery terminals jump up to 13.6VDC or more depending what the truck alternator system charge mode is in.

You will not get much charging coming from the truck setup however. The distance from the alternator and the size of the charge wire limits the battery charge alot. You may only get around 6 amps or so of charge current so it really just be thought of a good top-off charge for your trailer battery as your drive down the roads. You can still run down the trailer battery if you exceed the charge current coming from the truck alternator system.

This is what I had to do for my 2010 Ford truck setup. Your truck may be different so just do the TEST first to see if it proving a charge DC VOLTAGE at the trailer battery when your truck is running.

Roy Ken