Charging Battery while Towing

[ronandsue]

I am new to rving and have a problem with my battery. When i plug my rv into my tow vehicle i have not electrical in the rv. The battery is new and i towed it several miles and still no charge in the battery. I pluged the rv into 110 and i have electric through out the rv. It charged the battery that i had lights after disconnection from 110. The next day no power in battery.....

Is there something i can check to determine why i have no electric when connected to towing vehicle.

Since it is a new battery how long does it take to fully charge it.

Thanks for any Help

Ron

[Steve Collins]

In your 7 pin RV connector, pin #4 should be +12 vdc to the trailer. On some tow vehicles it is direct to the battery and always hot. On others, it may only be hot when the vehicle is running.

First, check to see if you have voltage at the connector. (Use a test light or multimeter.) If you don't you'll have to trace the wiring from the battery to the connector and see if it is connected, and if so, if there is a fuse in the line. Check to make sure the fuse is not blown. You may have a manual reset circuit breaker somewhere in the TV instead of a fuse.

Once you have +12 vdc at the connector, you move to check the trailer wiring. In particular, there is a master fuse in the line from the TV to the TT and there is a fuse on the line from there to the battery. If either of those fuses is blown, the juice from the TV won't reach the battery. Some TT's may have manual reset breakers in place of these fuses. In either case, they are 30 amp fuses and are not located in the power panel.

Can't answer your question on battery charging as there is no way to know from here how much you have discharged the battery at any given time. The more your battery is discharged, the longer the recharge time.

One other thing you may look into is to see if anything is constantly on so that it would run the battery down. Depending on the age of your unit, it could be any number of appliances or fixtures.


You did not specify what year your unit is, but if it is newer than '99 or so, there should be master cut off on the line. It may be on the A-frame or on the frame header behind the battery.

So it is wiring, cut-off switch, and fuses or circuit breakers.

[henryj]

A new battery will not necessarily have a full charge, but it should be decent unless you've had it sitting around for a month or more. I have not found driving to be a reliable way to charge the RV battery and I mean driving all day not just 20 min.

In the same way, the RV converter is not going to charge a battery in a couple of minutes. Don't forget the converter puts out 12V on its own so all 12V stuff will work even with a mostly dead battery as long as you're plugged into 110V shore power.

If your battery really is dead, I would charge it with an automotive type charger that has lights and a meter so you can tell what's going on. If you don't have access to one, plug into shore power for 3-4 days.

This meter plugs into the 12V receptacle and is really handy for keeping an eye battery charge (I noticed the link wasn't working. Go to Campingworld.com and search for 19983). I leave mine plugged in all the time, but, like Steve said, this is one of the things that will slowly bleed off the battery charge. I have a battery cut-off and use it when we're not camping.

Henry

[Steve Collins]

Things that will drain your battery without you knowing it:

1. The AM/FM radio/. It uses a little bit of current, even when you think it is off. Mine has a clock display that shows when the radio is off, and it will run your battery down all by itself in less time than you might think.

2. The onboard propane leak detector. Most of them use 12 vdc and not their own batteries.

3. The refrigerator. If you leave it running on propane, it uses a bit of juice to run it's control circuitry and such.

4. Any incandescent light. Most of our Sunlines have exclusively 12 vdc lighting. Leave one on; run the battery down.

If you store your TT without plugging it into a 110 vac source to run the convertor, it is a good idea to disconnect the battery in some way. Most Sunlines newer than mine have a battery cut-off switch of some kind. '99's and older did not come with them from the factory, but folks have been known to add them. (It is on my do-do list.)

We dry camp almost exclusively these days so power consumption is second nature to us, but many don't so it helps to think about these things.

[ronandsue]

I found the problem. On my F150 with towing package they do not install the fuses to charge a towed vehicle's battery. I found the fuses in the clove compartment and installed and now i have 12volts on pin 4 of the connector.

Thanks So much for all your help. It great to know you have an instant resource when newbees run into problems.

Thanks again

Ron