Just bought a used RV couple months ago and noticed that my house battery is really small. I have done some research and since I plan to do a bunch of dry camping this summer want to upgrade to 2 each 6 volt AGM batteries. I need to use my laptop and a printer, and would like to watch a 30"-36" flat panel tv in the evenings (can't miss my baseball games), and possible run a DVD player/game console for the kids. Question: what size inverter should I get, a pure sine or modified sine, and how do I wire the inverter? Do I need to wire the inverter between the battery and all of the house plugs? Or do you just plug the inverter into the house plugs and it will convert between DC into AC? If I plug the inverter into the cigerette lighter, doesn't that run of the motor battery and not the coach battery? And Lastly, if I am getting the new batteries and inverter, should I consider to upgrade my converter to a new converter/charger so that when I do turn on my generator in the mornings, it wil charge more effeciently? I don't want to spend a bunch of money on new AGM batteries and have my old converter/charger ruin them. Is that possible? Would like to do all of this work at the same time. Can I do it myself or is it too difficult to wire in the inverter?
Thanks!
JT
I would do a temporary install of a 600 watt or so pure sine inverter for your application. Temporary because for code and possibly insurance reasons a permanent install needs to be hard-wired into your house AC power distribution via transfer switches and it all gets complicated and expensive fast... You are not allowed to use temporary plugs to wire up a permanent installation, though many do.
Get the small inverter, read the instructions on DC power cabling, cable it to your new house batteries with a disconnect switch and a fuse. Put the inverter as close to the batteries as you can, but inside the RV so you can just plug a power bar into it and plug in your toys, TC's, computer etc. I've done exactly that for years in my Truck Camper, and in my bus I did a complete install of a permanent system, both ends of the scale...
I power my tv, dvd, laptop and charge small items with a Go Power 300w sine wave inverter.
I mounted the inverter behind the fuse-breaker panel. 12v connects to the main battery feed to the panel. 120v is wired into the entertainment area circuit with an automatic transfer switch. The wiring is very straight forward if you have done any home wiring before. The Go Power 300w has a provision for a remote power switch so with the touch of a button I have instant power.
JToad wrote: Just bought a used RV couple months ago and noticed that my house battery is really small. I have done some research and since I plan to do a bunch of dry camping this summer want to upgrade to 2 each 6 volt AGM batteries. I need to use my laptop and a printer, and would like to watch a 30"-36" flat panel tv in the evenings (can't miss my baseball games), and possible run a DVD player/game console for the kids. Question: what size inverter should I get, a pure sine or modified sine, and how do I wire the inverter? Do I need to wire the inverter between the battery and all of the house plugs? Or do you just plug the inverter into the house plugs and it will convert between DC into AC? If I plug the inverter into the cigerette lighter, doesn't that run of the motor battery and not the coach battery? And Lastly, if I am getting the new batteries and inverter, should I consider to upgrade my converter to a new converter/charger so that when I do turn on my generator in the mornings, it wil charge more effeciently? I don't want to spend a bunch of money on new AGM batteries and have my old converter/charger ruin them. Is that possible? Would like to do all of this work at the same time. Can I do it myself or is it too difficult to wire in the inverter?
Thanks!
JT
Hay JT, You are going to get a lot of opinions on this inverter thing, because each of us leads a different lifestyle. I thought I would throw in my 2 cent. We have fulltimed for the past 7 years. We started out with a 96 Bounder with no inverter. We boon docked some so it was a pain when we had no 120 volt power without starting the genny. I figured out what the power requirement would be for our 26” TV and VCR/DVD player and for the 2 laptops we use. I then purchased from Wal-Mart a 450 watt inverter for around $ 60.00. I hooked it directly to the house batteries with a fuse and heavy 12 volt wiring. It worked great and we would run the genny each AM while making coffee/breakfast then each evening while wifey made supper. The genny charged our batteries through the factory installed converter with no problems.
We now have a 03 Phaeton that came with a defective 2500 watt inverter and we have had it for a year. I purchased a 300 watt cig-plug inverter to run the laptops while on the road and I will be up grading to a 750 watt hard wired inverter when I get the time. I see absolutely NO reason to have 2500 watts for our lifestyle and would not spend the $ 2000.00 it will take to replace the defective one.
An inverter is only about 95% efficient so when it is turned on for any reason it is wasting battery power. This 2500 watt unit will waste ½ the power that I am actually using so out the door she goes.
In both coaches I have 4 wet cell deep cycle batteries and personally I believe AGM’s to be a large waste of $$$$ unless you have a situation that would prevent you from having wet cells.
Ron
If I were you, before I invested money in inverters, batteries, etc. I would do a little more analysis of what is needed to meet the objectives. The devices you mention individually don't take much "power", however, things add up in a hurry. The length of time each day that these devices will be run is significant.
Two 6-volt batteries, either AGM or flooded cell, wired in series typically have a capacity of about 200 amp-hours. For maximum battery life you don't want to discharge them more than about 100 amp-hours. At 12 volts this gives you 1200 watt-hours of "power" to use before you need to recharge. Inverters are not 100% efficient so at 115 volt side you may only have 900 watt-hours. (The specs for any decent inverter will tell you the efficiency.) Now read the power requirements on the label of each of your devices and multiply it by the length of time the device will be in operation. Add up the "watt-hours" for all the devices and compare it to the "watt-hours" that are available for use.
If you buy a good inverter that is intended for permanent installation, it will probably have a built-in charger for your batteries and you may not need a converter/charger. Recharging the batteries, if required on a daily basis, is a whole subject in itself.
I believe that if you search the web, and this forum, you will find a lot of information on how to "right size" your batteries, inverter, charging devices, etc.
Welcome to the forum JT! I installed a Morningstar 300 on my fifth wheel. While not cheap, you will find that you can run everything you mentioned through it. You can find others on the market much cheaper, but they will use quite a bit of your battery power just running themselves. I installed mine, hard wired, and I'm certainly no electrician. I did put a remote switch to turn in on and off, but found that it uses so little power we leave it on all the time. I have a dedicated outlet below the entertainment center to plug a power strip in, so I can shut down all phantom loads during the night. It worked so well, that I put in another dedicated outlet in the dining area, so DW could plug in her computer. That worked so well, I put in 4 other outlets throughout the rig. (Being retired makes for lots of spare time). We hardly ever use the big Xantrex inverter. Good luck on your project!
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2oldman wrote: Easiest is to plug your coach into the inverter, turning off your converter, and running HW and refer on gas.
I agree, I plugged my shore power into a receptacle wired to the inverter for many years before installing a manual transfer switch. In fact many will refer to this method as the most "foolproof" switch as the shore power can only be plugged into one thing at a time. In addition to shutting of the converter and running HW and refrigerator on gas, might as well turn off the circuit breaker to the air conditioning to be safe also.
Thanks all. One more question: Are there usually any plugs in an RV that are 12v wired, or are they all 110 and only powered when the RV is plugged in or with the generator on?
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