Picked up my Scamp

[Quint]

Well I just got back from Mobile where I picked up a '91 Scamp 13'. I spent the night in it last night and it's pretty sweet. It has three standard 110v outlets on it and I thought I could use them from the 12v battery for instance to power my laptop or a small appliance for a little while. I guess I was wrong. Is there any way I can use the 110v outlets from the 12v battery (I assume an inverter)? But I also want to use shore power at campsites for the 110v outlets. Is there a switch or something I can install that will let me choose where the power to the 110v outlets comes from? Where would I tap into this in my Scamp. BTW it towed great with the Nissan Quest. Thanks again.

[Gina D.]

Hi Quint! And congrats on your new to you Scamp. You're going to have lots of fun with it!

I don't know of a switching mechanizm that would do what you want to do for an invertor, a convertor does what you are talking about in the opposite direction tho. (Lets your 12v run off 110)

Folks with more "Stuff" than I have may chime in here with a better answer on that. My 110 needs are simple.

If you are only thinking of running your laptop and maybe a small current draw tv or such, you can by small handheld invertors that plug into your 12v outlets. I have one for my laptop and it works great.

Vector Inverter

You can also by bigger invertors and hard wire them in, then have dedicated inverted 110 plugs.

I do this as well for my video system, and when on shore power, I simply move the plugs into the "True" 110 outlets.

Inverters themselves can zap your battery regardless of the load on them, so it is best to use your shore power whenever possible, and the inverted power sparingly.

[Roger H]

Quint,

Congrats! You're gonna have a great time!

If you're planning on running 12v appliances from your battery, the most efficient use of that power is just to install 12v outlets (cigarette lighter style) in the trailer, wired directly to the 12v system. It's not, I'm told, a very efficient use of power to convert it from 12v to 120 A/C and back to DC with your computer's "brick" power supply. There's a lot of energy wasted in heat in converters/inverters. Your trailer's battery will last much longer if you run your gizmo directly from 12v dc outlets. Many computers and other DC powered appliances have converters that will allow them to run directly off of the 12v system. Truck stops are an excellent source for aftermarket 12v converters if you can't find what you need for your specific application.

Adding an inverter into the 120v system would seem to be a complex and unneccessary mod to me.

Roger

[Morgan]

Quint,

To expand on what Roger said, whether you power your computer from an inverter connected to the "brick" or from a DC to DC converter, the number of conversions is the same. Each conversion has a loss because none are 100% efficient.

An inverter connected to your battery changes the 12 VDC to AC and steps it up to 120 VAC. The "brick" rectifies the AC to the required level of DC voltage.

A DC to DC converter just does both those conversions in one unit. It changes the 12 VDC to AC, steps it up (or down) to the required level then rectifies it to DC.

The overall loss to heat will probably be close to the same with either hookup. You'd have to compare the conversion efficiency of the DC to DC converter to that of the "brick" combined with that of the inverter.

Making that comparison may not be easy because manufacturers don't usually publish the efficiency ratings of these units.

[Donna D.]

Well I just got back from Mobile where I picked up a '91 Scamp 13'.

Congratulations!!

I spent the night in it last night and it's pretty sweet.

You're gonna have soooo much fun! Don't forget to start a Journal of your travels and info. When the weather is bad or you're in your golden years you can read back and relive all the memories once again.

[Bill Abbay]

A lot of good advice in the previous posts.
I have to second the suggestion to buy a small inverter for the occasional need for 120 vac power, like an electric razor or small TV. As Roger and Morgan point out, using a small 12 VDC to DC converter for your laptop is more efficient than using the 12 VDC to 120 VAC inverter to supply your 120 VAC to (typically) 16 VDC external laptop supply. Each conversion is only 85-90% efficient.

A couple of years ago, I installed a 1500 watt hardwired inverter/charger. It was an ambitious project that works fine but realistically can't be justified from a cost/benefit perspective, at least on the scale that I adopted. While it's satisfying to be able to just plug in 120 VAC appliances when boondocking, it really doesn't come up that often when camping. (After all, that's why we're camping.) I have a Lind Electronics DC - DC power supply for my Toshiba laptop that runs off 12 VDC (you can find cheaper) and most of the time we're too far out in the sticks to watch TV.

So, congratulations on your "new" Scamp. You have acquired one of the most satisfying ways to "adventure" there is. Have fun!

[John D.]

I was watching QVC yesterday and they were advertizing a Rechargeable 12V battery pack that they say will jump start 15 cars with a dead battery before it needs recharged. Plugs into 110V to Recharge.
Also had a 12 V outlet, A built in Inverter with 110 V outlet, Air Pump to put air in tires.
This was about the size of a 12 V battery with a handle on top to carry it around.
Something liks this seems like it would work good to run a Laptop for a few hours and not run the Trailer battery down.
This would be something that you could use a lot of ways.
You can go to QVC and search for Inverters.
V20678 XPower Portable Jumpstarter and 150 Watt Inverter $62.55
V22464 XPower Plus Powerpack/Compressor 200W Inverter & Jumpstarter Introductory Price $72.75
$66.12
V23276 XPower Portable Powerpack w/600 Watt Inverter & Jumpstarter Introductory Price $152.50
$138.84

[Brian B-P]

Hardwired inverter/charger
Nice job Bill! Thanks for posting it. I had to smile when I saw the rat's nest of crimped connections at the umbillical termination and your terminal strip replacement; my Boler is twenty three years older than your Bigfoot and built by a different company but they could be twins - except that mine was harder to get to. I used an outside-mounted sealed termination box, but the idea is the same.
The automatic changeover - when shore power is available the outlets are supplied from it - appears to be a normal feature of the built-in systems, which addresses Quint's question.

Portable power packs
These were an active topic of earlier disucssion, with a lot of us in Canada getting the Canadian Tire house-branded units. I have one, and have used it mostly to keep a portable electic cooler going while parked, to boost vehicles in which I have left the lights on, and to pump up my rear suspension air bags for towing or load hauling. It is surprising how well such a small AGM battery (20 A-h in my case, rated for 600 A maximum current) starts a 6-cylinder van engine.

[Gina D.]

This was going to be my second suggestion as well.

I carry 3 individual 24 ah gel cells that are independant of the house 12v system. They charge with a wall wart, which are plugged into 110 sockets at all times. They charge whenever I have shore power. They live under my dinnette seats and are hard wired to outlets on the seat walls. One is portable for outdoor use.

I run my little invertor for my laptop off one of these, as well as my fantastic fan endless breeze. These two low draw items hardly put a dent in them even after running all day.

I have run my modem, laptop and a mini florescant light off just one of these for two days during power outages in my home before.

"Jump Its' are the same thing, just in a bigger package to accomidate all the outlets, handles and wot nots, I believe.

[Dan Meyer]

I've permanently installed a 400 watt inverter in my Scamp. Read all about this (and other) modifications on my web site; http://scamp.n0kfb.org/ and click on "Modifications and Repairs".

-- Dan Meyer