Adding Inverter

[Not_a_Clue]

I know this has been discussed many times, but I am looking for information specific to my situation.

Currently I have no inverter in my motorhome.
I have two six volt batteries that are 7+ years old

I am not going to add more batteries, space issue......
I will be probably be changing them out for two AGM's

The easiest path to take is a whole house setup. Replace charger with inverter/charger.
Since this is being done at a shop the labor vs more expensive hardware kind of balances out.

I was quoted two ways to go.

Inverter....MSW 1200w 70A charger.
Inverter....PSW 1000w 50A charger $292 more.

I know that on this setup I will have to watch what I run and not run to many appliances together.

I will be going full time later this year. I am not looking for a setup for lots of boon docking, just looking
to be able to overnight in a non hook up environment if needed, or maybe a couple of days with out hook ups.
I have a good working generator. I have a Traveler automatic dish on the roof.

Based on lots of reading I am leaning towards the PSW, of course.
This will be an exact replacement to size also matters.

Thanks in advance!

[pianotuna]

Hi,

Good plan. How much for the total install? What make of inverter?

Not a Clue wrote:
Thanks everyone for you input. I think I am comfortable with going with the PSW 50A/1000W.

I will not be using it for Microwave or AC or anything heavy output. I have a generator for that.
It will mostly be for evenings when we have no power and want to watch a little TV. We have 12v outlets for any charging of electronics.

[N-Trouble]

I did the shore power cord thing for two reasons.

1) I like to power the whole house.
2) Ease of install

I put a notecard on my inverter (300W GoPower) next to where I plug in the shore cord

- Turn fridge to GAS only
- Turn off converter breaker

For larger items like coffee maker and microwave I have an onboard 4KW genny.

[2oldman]

Excellent choice.

[Not_a_Clue]

Thanks everyone for you input. I think I am comfortable with going with the PSW 50A/1000W.

I will not be using it for Microwave or AC or anything heavy output. I have a generator for that.
It will mostly be for evenings when we have no power and want to watch a little TV. We have 12v outlets for any charging of electronics.

[dahkota]

Our coach came with 1200W MSW inverter that powers some outlets. It has worked very well for us. We have lost no electronics though we have boondocked/dry camped at least 200 days over the last year and a half.

One advantage of not having all outlets powered is we don't have to run around unplugging things when using the inverter. Having a lot of things on 'standby' can drain quite a few amps off the battery.

We have a 900W coffee maker and a 400W crock pot and both run fine off the inverter. Our microwave is not on the inverter and we have no need to add it - the generator will power it if needed but usually we can find something to eat that doesn't require it.

If we had to install a new charger/inverter, we would definitely go with the higher powered charger over the higher output inverter. It would get our batteries charged faster rather than using the batteries faster.

[wbwood]

coolmom42 wrote:

wbwood wrote:
I have a similar question. WE also have no inverter and I am looking at adding one down the road. It will be a pure sine wave one. My concern is how to install it. I could install it and just connect to the batteries and plug things it at the inverter or have it installed where it functions all outlets. I can't see running many things on it besides charging some cell phones or computers. We've done good with out one so far.

My question is how much can I expect for installation of one to run all the outlets (labor only).

If you have a 12V outlet anywhere, you can use it with a small plug-in inverter, instead of hard-wiring one. That will work OK for charging electronices. Also handy to use in the car.

The only 12 volt outlets we have are on the dash. We have 2 there, but not sure if either one of them is wired to the aux batteries. Will have to check. I already have a couple of those smaller 100w cigarette lighter inverters.

[Almot]

westend wrote:
Two 6V batteries will limit your inverter size to around 1000W as a big inverter operated toward the maximum rating will suck down the two batteries pretty quick. Most folks just need inversion for entertainment gear, charging/operating computers, and phones.

Yes.
2000W not only will deplete batteries fast, but will kill them faster too. 90-100A current from microwave is too much for 2*6V. 3 AGM, 100 AH 12V each, will work better.

Without microwave, toaster etc you don't need more than 600W. 1000W inverter will be plenty.

[Golden_HVAC]

1,000 watts is marginal for running a microwave that draws about 12 amps at 120 volts (1,400 watts input for the 1,000 watt rated output power). A microwave will run fine on PSW, but will be damaged on MSW.

I don't know what you plan on running, but a inkjet printer will work fine on MSW, but a laser printer required PSW, or start the generator while printing.

The A/C unit will require 1,500 watts, and will not run on MSW, your battery bank is to small to run it anyway.

A heating device like the coffee maker will run fine on either PSW or MSW, but your battery capacity is to small to run it very long, better keep the 1,000 watt coffee maker on the generator only. That is about a 100 amp load on the battery, or enough to take it from 90% full to only 50% full in about 10 minutes, and it would take 2 hours or more to get the battery back to 90% full with the 120 volt charger.

Personally I would keep the charger that you have, and install a couple of cigarette lighter receptacles. Then you can plug in a 300 watt inverter, small extension cord, and then run all the chargers (laptop, cell phone, ect) that you want, along with the TV, DVD, and such from the smaller inverter.

Have the cigarette lighters installed with #10 wire and a 20 amp fuse. This will allow the lowest voltage drop (due to the large wire) and work fine for the small loads, that a pair of batteries can handle. Then you can take the inverter to where you need the power, plug it in, run it a short time, and unplug it.

I have a 1,500 watt Trace M1512 inverter/charger that I installed in my RV. Normally I let my solar panels charge the batteries, and never turn on my 120 volt charger.

If I am dry camping, and watching TV, my total draw from the battery might be say 7.5 amps with the big inverter running, or only 6.2 amps if I unplug and use my 300 watt portable inverter.

You should consider a couple of solar panels. I would recommend a pair of 140 watt from this place, with aluminum frames, and mount them on the roof, run UV resistant wire (#10 from Home Depot) down the back of the refrigerator vent, to a charge controller, to the battery.

SunElec.com

Good luck,

Fred.

[pianotuna]

Hi,

You don't say how much the total cost of the inverters are--and what make and model they are. Be CAREFUL.

When you replace the batteries there may be good reasons to go to twin twelve volt AGM batteries.

My installation is to have an outlet powered from my inverter in the shore power cord box. I do need to do 3 things each time I switch over. 1 turn off the converter, 2 turn off the water heater electric, 3 switch fridge to gas.

If you plan to boondock I'd encourage you to add a solar system.

[coolmom42]

wbwood wrote:
I have a similar question. WE also have no inverter and I am looking at adding one down the road. It will be a pure sine wave one. My concern is how to install it. I could install it and just connect to the batteries and plug things it at the inverter or have it installed where it functions all outlets. I can't see running many things on it besides charging some cell phones or computers. We've done good with out one so far.

My question is how much can I expect for installation of one to run all the outlets (labor only).

If you have a 12V outlet anywhere, you can use it with a small plug-in inverter, instead of hard-wiring one. That will work OK for charging electronices. Also handy to use in the car.

[aslakson]

When we had our inverter/charger installed, it was wired whole-house (30amp coach). Not sure how AM Solar did it, but it's just like having an Uninterupted Power Supply for the coach - when the shore power is disconnected, the inverter takes over. When the generator comes on, the inverter starts charging. Of course, we have to remember to turn off the AC and electric WH before killing external power, but even when we don't, the worst thing that happens is that the inverter overloads and shuts down. Turn off the AC and/or WH, and restart the inverter, and all is well.

If you go with AGM, DO get a combination inverter/charger if it will fit in your space - AGM and Gel cells are happiest with a staged charging using different voltages. Most older chargeres don't do that.

FWIW, we have four 6v gell cells into a 2000 watt inverter, and we can run the whole coach (minus the AC and WH) for about 10 hours on one charge - that without changing any of our normal "plugged in" behavior (Microwave, TV, computer, etc). As a matter of fact, out electrical management system even has a 20amp setting we use if we're going to be dry camping for more than a night. With that, we could even run the AC - one unit only pulls about 6 amps after it gets started - but we don't.

al

[2oldman]

DrewE wrote:
If you have an electric water heater element, you don't want that powered from inverter power. A third thing to remember to switch.

Yes. Whole house is a real easy install, and real easy to dis-install if you sell the coach.

The downside is remembering what is to be turned off. If that's not something you trust yourself to do, then by all means don't do whole house.

[AllegroD]

You do not need 120v for cell phone charging. This is especially important if you are not adding more batteries.

[DrewE]

Personally, I wouldn't go for a straight "whole house" setup. I'd either want "almost whole house" or just one or two selected outlets.

You don't want the fridge running on AC power when the inverter's on, but using propane. That means remembering to switch it over (and switch it back to automatic) whenever you use the inverter.

You likewise don't want the converter, if it's a separate unit, to run from the inverter power. There's another thing to remember to switch on and off.

If you have an electric water heater element, you don't want that powered from inverter power. A third thing to remember to switch.

What appliances are you interested in running? A smaller inverter would be sufficient for TV and computer and charger usage. A 1000W or 1200W inverter is quite marginal at best for a microwave or most heating appliances (coffee maker or whatever). It seems to me rather a no-man's-land size for most people's needs or wants.