Installing a battery

[David Scott]

All of these replies are so helpful- you have no idea!

Gina, thanks for the concern you've shown- my little baby thanks you.

John and Sandy- I am thinking of all kinds of ways to minimize. If I do go the route of a cold cathode/ led light for a night light, do i have to install the wiring and if so, would it go directly to a fuse block running from the 12v?

Mike- thanks for advice on how to run the wires from the solar panels. I am thinking of starting with 15 watts and seeing how that does.

Flint- good to see you chime in here! Your advice and help has been priceless.

John- Thanks for breaking this down mathematically. I'm in the social sciences and all these conversions had hitherto been a bit fuzzy for me. So as I figure, I can charge my laptop and electronic devices (camera battery, etc.) in my car while driving... mostly. That leaves me with around 150 whrs per day if I am careful (150/12.6= 12 amp hours). Now, if I leave home with my battery fully charged that is 42 amp hours, around half of which I should consider usable (for the sake of the longevity of my battery). Let's say by the end of Day 1 I run it down to 30 amp hours. Thanks to a 15-watt solar panel, I could conservatively get 15watts X 5 hours full charge (it will be mounted on my roof so I won't be providing the perfect angle all the time) = 75 watt hours I will be returning to the batter (75/12.6 = 6 amp hours returned per day). That brings my 30 back to 36. So it would look like this:

Evening 1: Begin at 42 amp hours End at 30 amp hours
Evening 2: Begin at 36 amp hours End at 24 amp hours
Evening 3: Begin at 30 amp hours End at 18 amp hours
Evening 4: Begin at 24 amp hours Fourth night I could maybe run the night light

So as I figure, if I'm careful I could get 5 days, 4 nights with a 15-watt panel at approximately 150 whrs per day... I think

That was fun!

[John Blair]

David,

When I was in college many years ago, my friends majoring in the social sciences were surprised at how much math they had to take. Your calculations look pretty good. The only issue is that you may have damaged your battery on evening 3 when you went below 21 amp hours (1/2 of 42) to 18. So you need to lower your usage and/or increase the size of your battery or solar. When I do my calculations, I divide by two right off. So I would start with 21 amp hours:

-Evening 1 - 21 amp hours - 12 = 9 amp hours
-Day 2 - 9 + 6 = 15 amp hours
-Evening 2 - 15 - 12 = 3 amp hours
-Day 3 - 3 + 6 = 9 amp hours
-Evening 3 - 9 -12 = power runs out in the middle of the night (or you damage battery)

There are several options you might consider:

-get a little led light that is battery operated and use rechargeable batteries to use as a night light. That would save a bunch of energy. Or you could get one of those solar-powered garden lights and leave it outside during the day or in a place that gets sun if you are driving.

-Get a little larger battery or a spare one.

-Get one of the "jump-start" battery sets for a backup. Some of them also have inverters which you could use to recharge your laptop etc on non travel days. The one I bought also has an air compressor built-in, which is handy out in the boondocks.

-Make your solar panel portable instead of mounting it on the trailer. That way you will have options of placement. Otherwise you know the best camping areas will all shade your trailer and solar panel. Make up an extension cord to connect it. Use a big gauge wire (the smaller the number, the bigger the gauge) to avoid voltage loss. If it was me, I would use 12 gauge wire. My new solar (2-85 watt panels) uses 8 gauge.

-Someday, if power is really important, you can add in one of the little 1000 watt Honda generators... pretty light and quiet (but not cheap).

Have fun with it!

John

[Gina D.]

David, I ran for a year on just 15 watts. I did so using nothing electric but lights. Everything else was battery or hand powered. I built up to my 60 watts as I could afford to.

LEDs and Cold Cathodes are very simple to install. If you get the right leds, they will work directly off of 12v, so you can just tap off any 12v line you have running from your fuse box. They draw little current, so it is safe to operate them in parallel with any other item that might be on the same circuit.

You will need to wire in a power switch, also very simple OR you can simply add a 12v ciggy lighter type plug onto the end of the line to the leds and plug it into a 12v outlet. The switch looks a tad nicer.

The cold cathods are just as easy, however, they have a small invertor they need to operate. High voltage, low low current capability. Most come with a power switch.

[David Scott]

So I can't just put led lights into the existing 1141 sockets that are wired to the 12v system in the trailer?

On another note, if I do end up going solar, what do you think of this 60 Watt solar kit from Costco:

http://www.costco.com/Browse/Product.aspx?...ec=&topnav=

It seems to have everything, including the 7 amp controller, an inverter, and even a crank light... all for $300 sounds pretty good!

okay, 4am and the little one is drifiting back to sleep!

David, I ran for a year on just 15 watts. I did so using nothing electric but lights. Everything else was battery or hand powered. I built up to my 60 watts as I could afford to.

LEDs and Cold Cathodes are very simple to install. If you get the right leds, they will work directly off of 12v, so you can just tap off any 12v line you have running from your fuse box. They draw little current, so it is safe to operate them in parallel with any other item that might be on the same circuit.

You will need to wire in a power switch, also very simple OR you can simply add a 12v ciggy lighter type plug onto the end of the line to the leds and plug it into a 12v outlet. The switch looks a tad nicer.

The cold cathods are just as easy, however, they have a small invertor they need to operate. High voltage, low low current capability. Most come with a power switch.

[Gina D.]

David, yes, you can get drop ins. I get mine from Autolumination. They have just about everything under the sun (Excuse the pun)

I have seperate LED fixtures that are swithed so I can leave the incandescants intact and don't have to swap out bulbs. I rarely use the incandescants, even with shore power available, but I want them to be available just in case anyway.

The Costco kit looks great, tho I have heard tales of woe about the wire harness that comes with it. A couple members here bought one and had to redo the pigtail.

Those are the same panels I have, they work great. Mine was a 45 watt kit that came with a frame and it plugged right togther.

[Greg A]

When I bought my 13 Scamp in Feb it only had 2 12V dome lights and an empty battery box much like yours David.

I picked up a group 27 Deep cycle marine battery at Wally for $59 and 2 year full replacement. Pretty good ratings on it and seemed to be the best deal out there. If you need it replaced certainly should be a Wally not too far from wherever ur at.

Got the LED's from Gina's recommended place and they are awesome. 2-LED Domes were $10 ea. Ordering LED replacement bulbs for my 4 individual $10 JC Whitney bullet reading lights and good to go. As Gina said they have just about every replacement LED and a chart to match it up.

Put in wiring blocks from Home Depot for about $3 to split my 12V into separate circuits.
Wally has in-line auto fuse blocks that are about $1 which make it really simple to put fuses between each circuit for next to nothing.

I've run the lights for over six hours while working and the battery doesn't even drop.
I am adding the shurflo water pump about $90 bucks for the system, and will probably pick up the solar soon.

I agree with Gina, even plugged in I would use the LED's. I really like the lighting.

[David Scott]

Thanks Greg.

I was at Wally today and I think I bought that exact same battery (115 amp hours!). Shocking as it may be, the closest to me is about 20 miles away but I bit the bullet since the batteries are so cheap (and I needed some other stuff).

I am pretty lost now, though excited to learn. So I have the battery and am apparently ready to do the wiring. I just would love to understand fully the next step. I am conceptually "with it" and understand that the battery will supply the source to a fuse box (though I have NO idea what kind) and from there I can run wires to my existing 12v system as well as things like inverters (and a pump if I want it later). While there's a Home Depot closer than the Walmart, I'm just not sure how the whole system should look, what kind of wire will leave the battery to the box, what kind of box to get, what kinds of fuses I'll need, etc. God this sounds like a post from a 15-year old. What did Socrates say about being smart is equivalent to knowing nothing? God, I feel like a genius.

thanks for bearing with me everyone... This reminds me of when I moved to Germany and, though I had good intentions, I simply couldn't speak the language.

[Greg A]

David,

Here are the dome led's:

http://autolumination.com/fixtures.htm

Here are the reading bullets:

http://www.jcwhitney.com/autoparts/Product...0007211/c-10107

LED bulbs to replace #1003 in the reading bullets

http://autolumination.com/otherleds.htm

I put this 4 switch in at the dinette end wired all the new 12V lighting through it and can control the lighting in the entire egg from bed: (4 and 6 year old in the bunks at other end)

http://www.jcwhitney.com/autoparts/ItemBro...ID:100000221218

Wally in the RV aisle at ours:

Bussman ATC Blade Fuseholder They are wired with a #12 wire already to connect right in and plug in a 1-30amp Buss ATC fuse Whatever size Buss ATC fuses you need. I'm mostly using 10Amp.

30 amp Junction box at home depot in the wiring/computer aisle. They have various sizes but I'm using two four post one at front and one at the back to junction and split my circuits.

Couple of boxes of #10 Spade Terminals to hook up wires to the junction box.

Bunch of 14 ga wire -- Home Depot. I'm staying with Black and White which matches what already came in from the battery.

Couple of boxes of splice connectors- home depot

Bunch of wire nuts and electrical tape--home depot

Screw the Junction boxes to the plywood floor in convenient easy access locations, then wire one side completely hot from the battery White/Black White/Black. On the other side of the junction box pull your circuits in that end of the trailer and wire in a Buss ATC fuse holder on the black wire going to each set of equipment. IE to refrigerator White/Black with Buss fuse holder wired on the Black line.

If you print this out and go over to Home Depot they could probably work you through how to do it and different options. This is just how I am handling it and there are some really creative folks here in this forum that do some pretty incredible solutions. Of course, you can get creative as well, like my switch at the bed controlling the entire egg, etc.

Hope this helps give you some ideas. Sounds like you found the same battery at Wally.

[David Scott]

Thanks a ton Greg. I will print this out and get to work!