Added Battery to Tongue Today

[Kurt in BC]

Few weird questions regarding my deep cycle battery to the tongue of my trailer:

1. Is it okay to drill a small 8mm (1/4") hole in each of the frame rails to mount the battery box? I do not want to encourage frame cracking. For now its strapped down around the frame with some heavy duty zap straps but want something more secure.

2. Got the deep cycle battery installed and the 2 interior puck lights would not turn on. But....once I plugged in the trailer lights plug to my truck they worked.....does this mean someone spliced into the trailer lights and grounded my puck lights there? I assume this must be the case so......

Once I found out where they are grounded to.....where do I ground them to so my deep cycle battery will turn them on? Not sure whether I have to ground them to the frame or back to the battery....not too good with electricity. I want to install my fantastic fan so I want to get the battery thing sorted out first

thanks everyone....

PS - the deep cycle was only $65 at Costco!!


- Kurt

[Gerry]

Kurt, I had a tray built and welded onto trailer (Cost me a 6 pk of beer to local body shop) and drill holes though this to hold battery box in, but anyway I would think these small holes wouldn't cause a problem,
If all the other lights work off battery then the battery is grounded to trailer frame as are the lights working so those that do not run check to make sure they have good grounds to frame or other known grounded wire.
I have one heavy ground wire to the frame to the converter then to a bus bar and take all grounds (white) to all lights.
Gerry the canoebuilder

[Roy in TO]

Once I found out where they are grounded to.....where do I ground them to so my deep cycle battery will turn them on? Not sure whether I have to ground them to the frame or back to the battery....not too good with electricity. I want to install my fantastic fan so I want to get the battery thing sorted out first

Kurt,
I recently posted a wiring diagram in a thread here on FGRV.
At this moment, the diagram needs a little updating (a few minor name changes) and the "negative 12 V DC return" which I labelled in the first diagram as "ground" needs to be attached to the frame. I will do this from the negative post of my fuse panel. (You are not alone in being electrically challenged)

FYI my Boler had neither a converter nor a fuse panel and everything was wired to the trailer connector. I bought a Blue Sea fuse panel and separate main fuse to connect the trailer battery. I previously bought one of these smart battery charger / power booster / 12 V back up units from Canadian Tire that I can connect to the fuse panel and charge my batttery from under the front seat when connected to 120 V.

The 12 V DC wiring is continuous, by that everything must have a wire coming from the postive and one returning to the negative of your power source for the electricity to flow. Most of us lay people call the negative 12V return "grounds", because somewhere along the system they are "grounded" to the frame, that is they are connected to [b]both the battery and the frame. Just like Gerry says.

I have one heavy ground wire to the frame to the converter then to a bus bar and take all grounds (white) to all lights.
Gerry the canoebuilder

I found the Scamp wiring diagram to be very helpful, where the "ground" is shown in light blue (since white on white does not show up very well). That diagram is posted both here in the document center and on the Scamp trailer site. I downloaded it to my computer so I could refer to it quickly. Oddly enough, the Scamp diagram does not show the "ground" connection to the trailer frame. The "bus bar" is shown as all the light blue dots on the 12 V DC negative return labelled "white".

BTW what battery did you get at Costco?

Roy

[Kurt in BC]

thanks for the replies, very helpful. I am heading out for a few days camping and will tackle it when I return.

The battery I bought is one of the Kirkland deep cycle/marine batteries. Its not the largest one they had but all I am running is the 2 puck lights and the fantastic fan anyway.

[Brian B-P]

1. Is it okay to drill a small 8mm (1/4") hole in each of the frame rails to mount the battery box? I do not want to encourage frame cracking. For now its strapped down around the frame with some heavy duty zap straps but want something more secure.

If I were going to drill a couple of holes in the frame, I would want to put them in the side, not the top or bottom - this applies whether the frame is an open C-channel or a closed box section. In either case, the top and bottom are the most highly stressed, and somewhere near the centre line there is essentially no stress at all. That's why I-beams can have big lightening or access holes though the "web" connecting top and bottom, and why truck frames are perforated all over the place on the side, but rarely have a hole in the top or bottom flanges (also, sometimes the flanges are heat-treated to be harder).

When I installed my shock absorbers, I drilled two 1/2" holes right through both sides of the box frame rails for each shock mount... but not too near either top of bottom of the rail.

[Pete Dumbleton]

Brian's advice is right on target; put the beam or frame holes in the center vertically, rather than top or bottom, unless you really know something about it.

In my opinion, the presumption in the Scamp wiring diagram is that the negative 12VDC is connected to the 120VDC ground (green) inside the converter. The 120VDC green ground is connected to the Scamp's frame (fitting can be seen through driver's side fender well), but that connection isn't shown on the diagram. Also, the connection of the white wire to the tow vehicle frame, and thence back to the trailer through the hitch hardware, isn't shown.

[Kurt in BC]

So how do you run off the trailer battery when the trailer is not connected to the tow vehicle?

If I ground my trailer battery to the trailer frame and then run the 2 puck light grounds (negative) and Fantastic Fan ground (negative) back to the trailer battery that should complete the circuit...right?

[Brian B-P]

If -- in addition to the +12V connections from the battery to the lights -- you run the 2 puck light grounds (negative) and Fantastic Fan ground (negative) back to the trailer battery negative terminal that will complete the circuit... and it doesn't matter (for completion of the circuit) whether or not you ground the trailer battery to the trailer frame. I suspect that right now one of the trailer battery terminals is not connected to anything.

The tow vehicle charge/return wires and the battery are connected in parallel; either one of them will do the job of powering the stuff in the trailer. If the converter has a changeover relay (like mine) that relay switches the source of power between the battery/tug and the converter... but it does not separate the battery and the tug connection.

[Kurt in BC]

thanks Brian that made more sense. For now I have not hooked it up to charge off my truck so I grounded the battery to the frame and ran the items back to the battery for ground. Works well. I will eventually add a charging wire but thats enough for this summer.

I used a nice power distribution block under the counter (with 25 amp fuses) and installed a 30 amp fuse between the battery and distribution block to play it safe. I mounted this on the battery box allowing me to easily kill the power. I used 10 guage wire as well.

I have one spare outlet on the distribution block for adding something else later if need be and for now it carries a spare fuse.

I also added a cigarette lighter/power socket on the side of the cabinet for my daughter's portable dvd car player, etc.

[Kurt in BC]

Here is the power distribution block

[Brian B-P]

That's a nice tidy setup, Kurt.

Although I personally dislike glass-tube fuses (I'm always afraid of breaking one), it should all work just fine.
The main fuse mounted on the battery box seems like a good idea (mine didn't come with one and I have not yet added one) and is in an interesting housing. Is the top wire entry sealed against water? Where did you find it, Kurt?

[Pete Dumbleton]

Brian, both my Scamp and my previous Jayco had 30A fuses inside the battery box (in the Jayco, the battery box was metal, under the rear bunk and accessible from outside).

Kurt, both the fuse blocks in my trailers had a nearby or integral negative/return/ground buss to which the negative wires from the loads were fastened.

[Kurt in BC]

Thanks Bryan. The fuse attached to the battery box is waterproof via rubber gromets and/or O-rings although I would not submerse it in water as it does not look overly water tight. It just sits under the lid so it should be okay for my use.

Both items are made by the same company (EFX) and a friend of mine is a sales rep for the company in Richmond, BC. He got them for me at cost for use in my car but no got around to needing them. They are generally made for custom car audio and I am not too sure where they are sold. They also make some very nice battery leads for show cars.

Pete, I am also using a integral negative/return/ground buss but its not near as pretty as the EFX stuff!!

Battery Lead:

[Brian B-P]

I think these are the items which Kurt used:
fuseholder
battery terminal
fusebox
I generally wouldn't consider car audio stuff (more show than go), but in this case they look quite functional are built for substantial wire sizes, which are good features.

[Pete Dumbleton]

I fastened my heavier wires to my truck battery using one of these mechanical lugs.