Adding eletrical to enclosed trailer

You won't successfully run a hair dryer or a flat iron off any moderately sized inverter system. You can run a fan pretty easily, but with 12V fans readily available, there's little reason to get an inverter just for that.

As others have said, you cannot charge a battery with a charger connected to an inverter powered by that battery.

I would suggest that your 120V system be little more than a permanent extension cord wired into the trailer: a properly weatherproofed chassis mount plug on the outside, and an outlet or two on the inside. You can connect that to a generator or a wall outlet when you need 120V power. If you'll be hooked up to power much, it would be worthwhile to put in a charger/converter for the 12V system. This is about the simplest 120V system for modern RVs; bigger units differ mainly in having a higher power inlet and a distribution panel in the RV, and frequently by having a built-in generator with some sort of a switching mechanism to choose between the generator and the external line input for the 120V system. Usually this is an automatic transfer switch these days, but there are manual transfer switches, the simplest of which is just a socket connected to the generator that the normal input cord is plugged into when the generator is used.

If you must have a flat iron, there are non-electric ones available...ferinstance, this butane fired one.

Conversion van converted to camper
I have an 110 amp hour AGM battery hooked up to a 100 watt solar panel attached to roof. need a controller from panel to battery to not fry the battery. Sunsaver makes good ones for about $60. Several 12 volt plugs from that. I have a 12v--110v fridge--can run either way. Added some 12 volt plugs from vehicle battery. Run fridge off of van when traveling. I have a 2000 watt inverter for bigger draws and some small 100-200 watt inverters for smaller stuff.
For hookups, I got some good extension cords of 25 feet each.
This also has a generator which I converted from AC dedicated to being able to power anything in van off generator. Also have a decent battery charger.
I invented a 5 gallon self contained water system and have a porta-potty.

Hi,

A group 29 battery stores about 1300 watt-hours of which only 50% should be used.

Hair driers are a large load and would require 2 group 29 AGM batteries with a 2000 watt inverter.

Here is a simple flow chart.

Budget-->Energy Audit-->Battery bank size-->number of watts-->PWM or MPPT. What ever type of controller is chosen, make sure it has adjustable set points and a temperature probe that is on the battery.

One rule of thumb is between 60 and 150 watts of panels per 100 amp-hours of storage. The smaller the battery bank the higher the wattage needed (per 100 amp-hours). Here is a link to the rather special spreadsheet which includes an energy audit, that N8GS has created to help size solar battery charging systems!

Solar Spread Sheet N8GS

For a nice explanation of solar, try this link:

Golden rules of solar

Flat iron and hair dryer take way too much current to ever run off of an inverter, unless it is connected to a MASSIVE array of batteries. If she needs either of those items, you need to plug into a 120v source, either a generator or shore power at a pedestal in a campground. Also, even a 12v coffee maker will run your battery down very fast. Use an old fashioned coffee pot on a stove burning propane.

I have a 30 amp RV and have to turn off all of the other high power draws (air conditioner/water heater) if DW wants to use her hair dryer.

As others have pointed out, you can not use a battery powered inverter to run a converter to charge the battery. Again, you are looking at solar or a 120v source, and solar won't cut it for the high current draw items you named.

As others have said, your plan won't work. I won't repeat what the others have said, sufficient to say they are correct.

Revert to plan B, a generator.

You may have seen some of these already.

The 12 volt side

Handy

Deep

Best converters

Phred's poop sheets

Wrong, this wont work.

"So my plan is to add a deep cycle 12v battery (one to start with)and a 110V power inverter. So the obvious question is keeping the battery charged. From some things I've read I can run a smart/trickle charger from the battery and basically BACK to the battery thereby continuously keeping it charged. It will be charged off the vehicle when running, but we need a week of sustainable power at best."


You just described a perpetual motion machine. It wont work. You can connect a motor to a generator and connect the generator back to the motor and spin the motor but the generator will NOT power the motor.

There are energy losses all through the system and you could measure it in very technical ways but it wont work.


Rv's have 2 electrical systems. One system is 12 volts and it powers the lights, water pump, refrigerator control circuits, water heater control circuits, exhaust fans, etc. The other system is 120 volts ac and it powers the air conditioner, microwave, the heat element for the refrigerator, the heat element for the water heater. It also powers a key component in the system.

These 2 systems are tied together with a very important component. The CONverter. It charges the battery and can power 12 devices without the battery present. A CONverter and a battery charger can both charge a 12 volt battery but a converter can convert 120 v ac to 12 v dc and not need the battery in the system to do it. A battery charger usually wont do this. I wouldn't recommend not having a battery when using a converter but it will work.

You mentioned not needing a lot of 120 volt ac.

To charge the battery you will need to do one of these things or a combination of these things.
1. Use "shore" power 120 ac to run a battery charger or CONverter.
2. Use a generator to power a battery charger or CONverter
3. Solar

I'm not using solar yet so others will help you with that. 30 watts will probably let you keep a battery from going dead during storage, not much more.

Run any 12 volt devices that you can with 12 volts. DONT INvert. Running an INverter off a battery and plugging a phone charger or laptop charger into the inverter is a waste of energy. Get a 12 volt phone charger or laptop charger. The inverter uses energy just being turned on and not even powering anything.

Instead of inverting to run the curling iron or other heavy 120 draw items, maybe you could run a generator?

Good inverters are expensive, especially when you get up in size. I run a 600 watt pure sine INverter to power my televisions and some 120 volt small stuff. When I want 120 v high amperage for hair dryer or microwave I use a remote start Honda generator.

There are a ton of details to doing this yet it's actually very easy. You need to know how long you want to be able to stay off grid. You need to build a basic energy plan that let's you begin to size the components. You need to start with the amount of energy you will use and size the battery or batteries to that.

The smallest and lightest battery you would use is a group 24. Then in capacity you go to gp 27, 29, and I believe 31. These are called marine or dual. Marine/deep etc. They work pretty good but when getting into much INverter use or staying out for longer time frames or running something like a 12 volt/propane rv furnace, you would do much better buy going to two true deep cycle 6 volt batteries in series. If you have no batteries now, I wouldn't buy marine/deep. Get real deep cycles. They vary from inexpensive at places like Sams club ($89.00 for one 6 volt) to much more for good batteries like Trojan etc. There are also other options like AGM and be aware of the various charging voltages required by them.

You have a ton of research to do before you buy components but you have come to a great place with a lot of knowledgeable people.

Give everyone some ideas of what you picture your camping style to be. Make a list of all the things you want to power and error on the high side. You may not watch tv much but you may if it's rainy and cold. If your system is a little to big, you wasted a little money, if it's too small it's going to stink. There are a bunch of variables involved here and many ways to do this. Everyone finds what works for them. If you will be hitting a campground every few days to charge up it's completely different than a person who wants to stay off grid all the time. You become your own energy company.


Here is just one scenario

1. Two 6 volt GC2 batteries in series which gives you a LARGE 12 volt battery. Either a converter like Progressive Dynamics ($160.00) or a good battery charger. When I say good I mean $160.00 to $400.00 Maybe an Generac or champion generator ($400.00 ish) that could fire up just for hair dryers and some battery charging. If you want the best get a Yammie or Honda.

To me, if you want to invert much, I would go with 4 gc2.

When you start talking battery charging it opens a whole different door. Some converters charge slowly and that's not a problem if your rig is sitting at home waiting to go out in a couple weeks. It's a real pain if you are burning fuel to run a genny hour after hour.

To me just because a campground let's you run a gen from 8:00 am to 8:00 pm doesn't mean I should. I want as short of run time as possible.

You can't run a charger off the battery and put more back into the battery then you are taking out. It don't work that way. In order to run a flat iron, and/or hair dryer you need a substantial amount of watts. You are not going to get that plus your lights, fan, etc. for a week out of a battery. You can get the lights, radio, coffee maker and fan (all for intermittent use) for a week out of the battery, that's about all you can expect.

I don't know, maybe someone else would know, but I don't think you will ever run that hair dryer reliably, once a day for a week, off of solar, plus your other loads, without spending a significant amount of hundred dollar bills. And if your panels are at all shaded, a overcast day, whatever, you just killed your solar power.