Newbie Questions - Electrical

KevinandCindy

Hi all,

We just purchased a used 2015 S Maxx and are complete novices to RV's but not camping.  I have a few questions regarding the electrical system.  It seems that the converter does many things automatically but I am confused on the interface between the trailer battery and the Tow Vehicle (TV?).

1.  When the T@B is connected to the TV via the 7 pin connection and the TV engine is running, does the TV charge up the T@B battery?
2.  If the T@B is connected to the TV and the TV is not running, will the use of appliances drain both the T@B battery and eventually the TV battery?
3.  Is it best to disconnect the 7 pin when camping and using only trailer battery?  Is it best to only have the 7 pin connected when towing?

Hope these questions are not too naive, but that really is our case.  The information we got with our purchase doesn't cover all our information gaps and hope to not burn out an electrical system or end up with a dead TV battery due to my ignorance.  We will be taking a shake-out trip in December when time allows but want to get as educated as possible.  Thanks for any help and hope to be able to contribute to the group once I am a little higher on the learning curve.  Kevin & Cindy

jkjenn

These are much the same questions I had, Kevin and Cindy. Let me give you my take on them.

1. When the T@B is connected to the TV via the 7 pin connection and the TV engine is running, does the TV charge up the T@B battery?

Answer: Only if you have a charge wire that runs from your battery to the 7 point connector. The easiest way to determine this is the take a voltmeter and check the prong that is at the one o'clock position on the 7 pin connector. Pot the positive lead on the one o'clock position and the negative on some thing that is bare metal (not painted.) If it was not wired with a charge wire, an RV dealer can do this for you.

2. If the T@B is connected to the TV and the TV is not running, will the use of appliances drain both the T@B battery and eventually the TV battery?

Answer: If you have a charge wire, yes, the T@b battery will drain your TV, especially if you are running the fridge on battery.

3.  Is it best to disconnect the 7 pin when camping and using only trailer battery?  Is it best to only have the 7 pin connected when towing?

Answer: If you are doing more than stopping for more than 15 minutes, always unplug the T@b. If you are afraid of running down the TV battery in the event you forget, you can have a battery isolator installed that would stop charging when the TV is turned off, or, install a master on/off switch to the battery, that would cut off supply from the battery to the T@b.

I unplug the T@b when I do more than stop to pump gas, generally. I don't heaved an isolator or a master on/off switch.

KevinandCindy

Thanks JKJenn,

That helps a lot.  At least now I can do some more checking about my set-up and speak with some intelligence if I need things to get changed.  Thanks again.

SunnyTAB

Great answers Jenn. I was "guessing" the answers and got them all right according to you.

Kevin and Cindy - never feel uncomfortable asking questions. Just when we think we have it figured out, something new comes up and all your questions will probably help everyone. I thought if you had a 7 pin on your tow vehicle then it charged the T@B battery for sure. We started by running the 7 pin to our 4 pin, and we definitely didn't have charging then bc it was one of the 3 pins not available. Charging only happened once we have a 7 pin hardwired onto our TV. 

 

We always unplug unless, like Jenn said, we're just stopping for gas.