DC to AC Inverter Sizing and Installation

[out4stlhed]

I am considering installing a DC to AC inverter to operate a few "essentials" TV, hair dryer, etc. (not at the same time).

I have been researching them and need some suggestions on wattage, how long can i really expect two new 850 amp batteries to last.

I have no problem spending the a couple or three hundred $'s if I get the performance that i expect.

Any other thoughts or suggestions are welcome.

Thanks in advance

Greg

[NWJeeper]

First of all, what kind of batteries are they? I don't know of any battery that in a pair would give you 850 amp hours unless they are out of an electric forklift and those are usually way too big for an RV. I think you may be confusing CCA for AH (cold cranking amps vs amp hours). The typical "deep cycle" battery that most RVs come with is a group 24 which is really not a true deep cycle and only has about 84 amp hours. A pair of them would be a little over 160 amp hours. To illustrate I have 6-6volt golf cart batteries, or 3 sets of two which gives me 720 amp hours at 12volts. Thats 240 amp hours per set times 3 sets. I currently run an 1800 watt inverter, which would power my microwave but I would never do it, just draws too much.

Now, to run a hair dryer off of batteries you have to know the wattage of the dryer. Most are 1500 watts which would require an inverter equal to or greater than 1500 watts. On a typical set of RV batteries it won't take long to drain them.

High wattage items such as hair dryers, microwaves, space heaters, heated blankets are best run on shore power or generator. You really need to size the inverter to the battery bank.

There are lots of good web sites that really explain this well and I have gone over it in another thread in much greater detail and also shows the math involved. Do a search of the forum for "inverter" and you might find it.....

[KyDan]

Yeah, like jeeper said-- anything that's made to produce heat is gonna be tough
to do on battery power. Not impossible but tough.
Coffee pot, blow drier, space heater, toaster, waffle iron, microwave all use LOTS of watts.

You can get a pretty nice generator for $300 that will run the above items one at
a time but it won't be super quiet.

We are a bit more minimalist. On those occasions when we don't have shore power
we do without toast or we can toast bread using a little folding coleman stove
top toaster. Boy scouts use them and they are still available in the camping isle
of Wal-Mart and other dept stores in season.
We perk fresh coffee using a stove top coffee pot also available in the camping isle.
My wife has learned to do her hair without a blow drier on these occasions.
(That's what they make ball caps for!!!)
Now the TV is a different story. We can power our LCD tv and DVD player off battery
power. My DVD player is 12v and my tv runs off a little cigarette socket inverter that
you can buy at WallyWorld for under $25.

If you're interested in a generator, check out this thread
http://www.forestriverforums.com/for...light=champion
Several folks have purchased the champion generator and are satisfied.
Keep in mind the cheap gensets are noisier than the expensive Honda and Yamaha.
Life is full of trade offs!

Happy Camping!

[NWJeeper]

Originally Posted by KyDan

Yeah, like jeeper said-- anything that's made to produce heat is gonna be tough
to do on battery power. Not impossible but tough.
Coffee pot, blow drier, space heater, toaster, waffle iron, microwave all use LOTS of watts.

You can get a pretty nice generator for $300 that will run the above items one at
a time but it won't be super quiet.

We are a bit more minimalist. On those occasions when we don't have shore power
we do without toast or we can toast bread using a little folding coleman stove
top toaster. Boy scouts use them and they are still available in the camping isle
of Wal-Mart and other dept stores in season.
We perk fresh coffee using a stove top coffee pot also available in the camping isle.
My wife has learned to do her hair without a blow drier on these occasions.
(That's what they make ball caps for!!!)
Now the TV is a different story. We can power our LCD tv and DVD player off battery
power. My DVD player is 12v and my tv runs off a little cigarette socket inverter that
you can buy at WallyWorld for under $25.

If you're interested in a generator, check out this thread
http://www.forestriverforums.com/for...light=champion
Several folks have purchased the champion generator and are satisfied.
Keep in mind the cheap gensets are noisier than the expensive Honda and Yamaha.
Life is full of trade offs!

Happy Camping!

Dan has the right idea here. We too use a stove top percolator for our coffee when we are dry camping. Our friends asked "what's that?" LOL. If my wife wants to blow dry her hair we start the generator. On our last motohome we did about the same thing with a cheapo 700watt inverter from Harbor Freight and ran just the TV, DVD, Sat Rec. with it. With our new Georgetown we went a little more expensive with a true sine wave inverter hardwired to power all the outlets except the microwave (it's on it's own circuit and I don't run it from batteries anyway) Keep in mind that a lot of today's electronics, especially LCD TVs don't like the modified sine wave or MSW inverters which are the cheaper ones. Xantrex makes a more expensive inverter that is MSW and touts it to be "almost a true sine wave" but as I found out the hard way the TVs in our rig don't like it, lots of "sparkies" on the picture, thus I had to pay more than twice as much for a true sine wave.

Keep in mind that when it comes to using the batteries to power AC items there is no free lunch here, it is expensive in terms of battery power used and sometimes the pocketbook. If you can find things like DVD players and TVs that run on 12V like KYdan you are much better off. Leave the high wattage items for a generator....

[out4stlhed]

Thanks for the input.