I want to power my outlets off of battery - Inverter Questions

[dagmandt]

Hi guys,

I have upgraded my batteries and have a separate charger set up for those. I have a travel trailer with the typical converter/charger but am thinking about inverters. I'd like to have power to some of my outlets on battery power. I don't have the cigarette lighter style plugs anywhere so the small portable inverters are useless for me.

I need to learn about how these are installed and what my options are. I imagine I would install one near my circuit breaker panel and would think I run the battery power in and it would have 110 in and 110 out and would switch between the two depending on the availability of 110. Am I simplifying this too much?

I see a bunch of inverter/chargers but I already have a charger with my converter. would I replace the converter with the inverter or use the in-line?

Any resources for me to learn?

Thanks,
Darren

[Dr4Film]

Inverters should be placed as close to the battery bank as possible to minimize having to use larger gauge wire than needed. But they should NOT go in the same compartment as the batteries!

Some inverters come with built-in transfer switches that will pass through 120 VAC when hooked to shore power.

Then using romex to the new outlets that you want to use. You could daisy chain them or go from the inverter to a distribution box and then to the outlets.

These two documents are great for what you need to get started.

The 12volt Side of Life (Part 1)

The 12volt Side of Life Part 2


Dr4Film ----- Richard

[Scarab0088]

This is a great mod to make to any RV.

It can be very complicated with transfer switches and hardwire connections to the AC breaker panel...I will let others talk about that.

It can also be very easy to install - and this is how I did it.
1. Buy the inverter you want based on cost, wattage you want, and modified or pure sine wave (pure is more expensive and better for sensitive electronics).
2. Install the inverter near your battery bank because DC voltage drops more on long wires than AC does.
3. Run an extension cord from the inverter to the shore power cord (make sure the cord is protected from sharp edges and of proper cable size for the wattage of the inverter).
4. Switch off the converter/charger to stop the "dog from chasing its tail."
5. Plug the shore power connection into the extension cord from the inverter.
Viola' you have inverter power. When you have shore power or external generator, the inverter gets unplugged...no risk of accidentally running both. If you have a built-in gennie, the transfer switch in the gennie will prevent running both.

If your TT has an exterior shore power cord connection, that connection could be modified for a cleaner look, but not required.

I had this set-up on my last TT and copied it on my current Class A that came with no inverter...powers the whole RV, there's no transfer switch to break and it works great.

Best luck

[Caveman CBB]

Ya, you need to put the inverter near the batteries and run the heaviest 12 volt cable you can find between the batteries and the inverter. You will most likely have to have it custom made. Then the easiest way after that is to run new 110 volt wires to new specific outlets in you camper. When I did this my inverter had standard outlets on the front of it and I just used extension cords strung out when I wanted to run the inverter. I will admit that looks a little messy but, it was very easy to set up I didn't dry camp all that often so I just curled up the extension cords and put them out of the way when not in use.

[dagmandt]

Thanks for the info so far guys. I'm reading as I go.

Here is what I'm thinking after reading the links and responses.

I could probably get away with a 750 watt inverter with transfer switch. Would mount it in my forward compartment, that is the closest I can get in a guaranteed dry area. It would still have 6 feet of cable to get to the batteries though. I can go big on the wire though to help.

I'd like to somehow tie into the shore power 30A romex so the transfer switch will work and so I can supply power to all the outlets so I can choose which ones I want to use for what. No microwave but I would have the option to charge my phone, laptop, or run the DVD player from any outlet. Most of the transfer relays appear to be only 20A though.

Not that simple? Seems feasible but I don't have access under the TT because it has a riveted barrier. I can get to certain areas though but the 30A shore power line goes into the converter of course which is mid-trailer. I could pull that from the panel and put in a junction box to take it forward to the inverter location then back to the panel. Seems doable.

Question: How do I get 12v to my 12v appliances like my LED lights and 12v TV if I disable the converter and use the inverter while on shore power?


This looks interesting with 30A switch and is pure sine wave. Good price for what it is but more than I wanted to spend.
http://www.theinverterstore.com/1500...r-charger.html

[dagmandt]

Originally Posted by Scarab0088

This is a great mod to make to any RV.

It can be very complicated with transfer switches and hardwire connections to the AC breaker panel...I will let others talk about that.

It can also be very easy to install - and this is how I did it.
1. Buy the inverter you want based on cost, wattage you want, and modified or pure sine wave (pure is more expensive and better for sensitive electronics).
2. Install the inverter near your battery bank because DC voltage drops more on long wires than AC does.
3. Run an extension cord from the inverter to the shore power cord (make sure the cord is protected from sharp edges and of proper cable size for the wattage of the inverter).
4. Switch off the converter/charger to stop the "dog from chasing its tail."
5. Plug the shore power connection into the extension cord from the inverter.
Viola' you have inverter power. When you have shore power or external generator, the inverter gets unplugged...no risk of accidentally running both. If you have a built-in gennie, the transfer switch in the gennie will prevent running both.

If your TT has an exterior shore power cord connection, that connection could be modified for a cleaner look, but not required.

I had this set-up on my last TT and copied it on my current Class A that came with no inverter...powers the whole RV, there's no transfer switch to break and it works great.

Best luck

This is also an interesting approach... might have to ponder on this. will save a lot of wiring and headache. I don't really need a charger inverter anyway as I have an Iota charger that is incredible.

I just need to figure out if I can switch off my converter, and if I do will I continue to have 12v to my 12v appliances. I suppose using my battery cut-off switch would accomplish the same thing.

[Scarab0088]

Originally Posted by dagmandt

This is also an interesting approach... might have to ponder on this. will save a lot of wiring and headache. I don't really need a charger inverter anyway as I have an Iota charger that is incredible.

I just need to figure out if I can switch off my converter, and if I do will I continue to have 12v to my 12v appliances. I suppose using my battery cut-off switch would accomplish the same thing.

All the devices that run on shore power should have a breaker on your AC panel...so, you can switch the breaker for the converter/charger if there is no other power switch for it. Not best, but it is simple and works 100%.

I avoid installing "combo" devices like a converter/charger/inverter, because combo units are often more expensive than the separate components...and if 1 part fails, it often requires a full replacement vs. just fixing the 1 part that failed.

For running 12VDC items, your DC system should always be hot until you switch-off the batteries. Turning the converter/charger off should not kill the DC system...and you would need the 12volt system running for any inverter set-up.

An inverter is just a fancy 12volt appliance, I would not make any mods to that system when adding the inverter...keep everything as designed...just add the inverter as physically close to the battery pack as possible. Special cables are not needed...I found heavy gauge wire cables with eyelet ends at Wal*Mart.

Best luck with what ever system you build

[dagmandt]

Ok, I'm researching myself into a circle. I have a few questions maybe someone can set me straight.

Long post alert!

NOTE: I'm only considering Pure Sine Wave

1. I have a TT with a Converter/Charger at the electrical panel.
2. I have a separate Iota 55amp 15.5v charger I have wired up for proper charging of my dual 6v Crown battery bank. (charges in 2 hours flat via genny)
3. I want to introduce an inverter into the mix so I can run all outlets on battery for short periods when required. IE: hair dryer, laptop charge, phone charge, DVD player, occasional power tool. I have a Honda 2000i for longer periods and charging.

I see that I have two main options.

1. Replace or somehow augment(?) the Converter/Charger with an Inverter/Charger. How do I power 12v if I no longer have a converter in the mix? I know battery will power it but when on shore power do I have to then leave the battery cut-off switch on in that case? I guess the question is, if I remove the converter/charger what powers all my 12v appliances when the converter used to do it?

2. Purchase an Inverter without charger and wire it near the batteries with an outlet which I can plug shore power into. Find the breaker for the converter/charger and ensure it is off while doing this or wire up a transfer switch.

I like option 2 above for simplicity and separation of components. I could use the converter/charger for maintenance charge on the batteries since they don't charge well at all. I have the Iota for rapid and full charge and would have the inverter for those times I want to run outlets off of battery.


I was looking at Magnum 1000 watt inverters but they only come in an inverter/charger for pure sine wave and besides that, they are double the price of most others if not triple. SPENDY! I'm trying to keep things under $500 for just an inverter. I do like to buy top of the line components but I'm having to be budget minded on this one within reason. I want a good inverter, just don't need the top of the line if a decent one will suffice.

I'm searching the forums, are the Xantrex inverters decent? Reviews on Amazon seem positive. What about those here with experience? It seems I could get one for my budget easily.

A final question: How do I know if the full wattage is available through one outlet of the GFCI? I've seen posts where people say it is split between the two outlets.

Thanks for any continued advice.

[dan-nickie]

There are a couple of things that maybe I can help you clear up.
When you are on shore power, you should not need to use the inverter. Turn it off.
When your converter is turned off, your12 volt lights etc work off the battery. Basically the same as when the converter is turned on, and not plugged into shore power.
I hope this helps a little.

[Dr4Film]

If it were me, I would purchase the Xantrex 1000 ProWattSW and also get the remote and the transfer switch.

Power Inverter, Pure Sine Wave Inverter, Marine Inverter, PROwatt SW

If you purchase any of the off brands then you will have to piece meal other components together to get it the same as the Xantrex. Buying the Xantrex is a complete package.

I have been using a Xantrex/Trace RV2012 2000 Watt MSW inverter in my coach since it was delivered in 2001. It has worked flawlessly since then.

They are great products but if I had to replace this one, I would definitely go with the Magnum PSW for my RV. They are pricey but when my coach is R HOME, I feel the extra cost is worth it.

Dr4Film ----- Richard

[J Birder]

Originally Posted by dagmandt

This is also an interesting approach... might have to ponder on this. will save a lot of wiring and headache. I don't really need a charger inverter anyway as I have an Iota charger that is incredible.

I just need to figure out if I can switch off my converter, and if I do will I continue to have 12v to my 12v appliances. I suppose using my battery cut-off switch would accomplish the same thing.

This method should work for you. You most likely have one circuit breaker in the panel that controls just the converter. That would make it easy to turn it off. One word of caution. Sooner or later, you will get distracted, and forget to turn it off like I did. My batteries ran down real quick. To avoid the possibility of doing it again, I connected the coil of a normally open relay to the inverter output. Then, I used the contacts to interrupt the power to the converter.

Now, when the inverter goes on, the converter goes off. I also connected t red neon pilot light across the relay, and a green neon pilot light across the converter. That enables be to check the status at a glance.

Joel

[Dick Noble]

I wonder if you are trying to make this more complicated than it need be? I wired our 5er so that I could use an inverter (1,850 W) for a single circuit. It was actually part of a solar system but should work the same. Converter (or solar or generator) charges battery, battery powers up the inverter, inverter feeds through a switch to a single circuit (120W). Switch has three positions - "invert". "off". "shore". I used # 4 welding wire for all 12vdc runs. I also installed in-line fuses at the batteries and at the inverter for safety. Most difficult part was getting into the junction box and finding the right circuit to put the control switch into. I do wish that I had installed an inside tell-tail so that I could monitor the batteries when in use. I did find a "battery minder" on-line that let me plug into any 12v line and see what the battery's charge level was. It has limited functionality.

This make sense?

[dagmandt]

Thanks guys. Yes, all the advice makes sense. I just tested my wife's hair dryer with a Kill-a-watt and found at the settings she uses it wants 1,400 watts and 12 amps. Guess I need to step up to the 2000 watt.

I like the idea of wiring the relay in. I will definitely consider doing that.

Another two questions:
1. With the GFCI plug on the inverter, will I have issues with it tripping if I were to connect it to the shore power line? I've heard people having this issue and replacing the GFCI (voiding the warranty) with a standard plug.

2. Will one side of the outlet supply a full 2000 watts?

So, depending on the answer to the above, here is my new slightly modified plan:

1. Use the Xantrex 2000w inveter
2. Wire close to battery of course
3. plug shore power into the inverter when needed. I will purchase the remote on/off switch.
4. Will eventually, if not immediately install a relay to cut off the converter when the inverter is in use.

Thanks again guys. I hope I'm not being too annoying. I just don't want any "gotchas" when I commit.

Darren

[Scarab0088]

For the OP's (original) questions (we were typing at the same time):

1. "I want to introduce an inverter into the mix so I can run all outlets on battery for short periods when required. IE: hair dryer..."

There are few blow dryers that are under 1200Watts (plus - expect 120-130% peak demand at start-up). To do this the OP needs a bigger inverter (pick the size of the largest load you expect to use).

2. Magnum and Xantrex/Trace are good equipment. My inverter has a Chinese name - but I bet the insides are the pretty much the same. Best luck with equipment selection...check customer feedback, but none are perfect.

3. GFCI outlets should not reduce the amps available at any given outlet (unless there is a problem in the outlet). And all individual outlets on an given circuit " should" have the same amps available. The limiting factor (as designed) is the breaker which should be less than the wire gauge rating used in the circuit. The amp rating for any circuit should be marked on the breaker panel. You can test this with the proper test meter.

Finally,
I forgot to switch-off the converter/charger 1 time when first using the inverter. It didn't break anything - it was just a waste of energy and will drain the batteries faster.
I didn't install a transfer switch, because they all break sooner or later...just do a quick search on iRV2 and you will see.
Instead, I made switching-on/off the converter/charger a part of the inverter connection routine - WHENEVER I move the shore power cord, I ALWAYS switch the converter/ charger.
And, my routine is very simple...the shore power cord is ONLY disconnected from the inverter when I have shore power...otherwise it is always set-up to use the inverter (has it's own on-off switch).
With a built-in genie, the only exception is that if I want to charge the batteries on the generator - then the converter/charger is switched-on, but only while the gennie runs.

The OPs #2 choice is what I have - works great and is very simple to install and use.
Hope this helps.

Best luck