Finally buying a strong inverter. How many batteries to buy?

[Cheryl_B]

PowerTech On Advanced Technology PURE SINE WAVE Inverter 3000W Cont/6000W Peak, 12V DC to 120V AC w/ Black&Red Cables w/Ring Terminals, Remote Switch, Protection System & 4 Output Sockets PS1004

That is what it says on the website I'm buying it off of. (Not sure if the rules here say we can say the name.) How many batteries and what is a good brand and model (excuse my ignorance. I know it needs to be a deep cycle but don't know much more) will I need to keep the inverter humming?

I'm sick of campgrounds draining my funds. I'm ready to do more boondocking and I'm heading out West, where there are more opportunities to do so.

If I pay a guy to install these for me (new batteries and inverter), what's a fair price? And how long should the job take? Thanks allot.

[Sam_Spade]

Cheryl_B wrote:
Yeah, I've pretty much been talked out of every idea I've ever had and asked about on this forum. Thanks, though. No sarcasm intended.

People are saying what they are because......either they have made a similar mistake in the past OR they know someone who has.

Would you prefer that they encourage your ideas.......and let you find out the hard way which ones are just impractical ??

[pianotuna]

I'm set up to "live" with 34.5 kwh or less per day in the summer time (when the living is easy). Oct 15, 2016 my use was 20 KWH in a 24 hour period. That number covered heating, water heating, cooking and all other loads. Currently (12:16 local time) I'm harvesting about 156 watts from the solar system.

From November through April 1st I need access to about 96 kwh per day with a peak load of 7200 watts. Of course that varies depending on weather.

For a place to look at how solar can be done, surf here: https://freecampsites.net/adding-solar/

[MEXICOWANDERER]

ADVICE,

Cheryl,
The only answer that makes sense, is self education. Self education differs utterly from exposing one's self to a barrage of opinions.

The answer lies in learning from OFF-GRID, alternative energy papers, discussions and forums.

Start out easy. Here is an online recommendation introduction that is free. It makes perfect sense.

http://www.motherearthnews.com/homesteading-and-livestock/living-off-grid-how-to-calculate-the-size-...

[azrving]

People have just given various ideas because there are many ways to accomplish how we power our RV's. We aren't the ones who would talk you out of anything, physics and the available technology does that, we just try to explain what your options are. I call it an energy management plan and we all have one no matter if it's a wool hat and long johns in a tent or a $800,00 DP. Air conditioning is usually the biggest glitch.

[SidecarFlip]

Either that or just go with a couple batteries and kill them in 30 minutes or so.

No way can you run your ac without having a huge bank of batteries, way more weight than your RV can carry.

You could go with Lithium Iron phosphate batteries that you can discharge to nothing without harm but the cost is prohibitive, about 800 bucks a pop. 4 of them would cost more than your older RV is probably worth.

[JimK-NY]

Cheryl_B wrote:
Yeah, I've pretty much been talked out of every idea I've ever had and asked about on this forum. Thanks, though. No sarcasm intended.

It is a shame that others are trying to talk you out of your plans. Let me see if I can answer your questions without adding any negative comments.

You had asked about the number of batteries you would need and mentioned running your A/C unit. A typical RV air conditioner uses about 12 amps at 120 volts which is 120 amps from 12 volt batteries. If you want to run your unit 50 percent of the time for 24 hours that would be 120 x 24 x 0.5 equals 1440 amp hours. The typical car sized battery is about 70 amp hours and you can safely use half that amount. You should be able to get by with about 40 batteries (1440/35). Of course if you get larger capacity batteries, that number would drop.

You also asked about charging the batteries with your RV alternator. That is difficult to estimate since it depends on the alternator, wiring and other several other factors. Alternator output is low if you RV is just idling so you probably want to get out and drive at highway speeds to get the best efficiency. As a rough estimate I would expect that you should be able to charge your batteries with a nice cross country trip of 2000 or 3000 miles. You also mentioned the option of using a generator. You also need to be sure you have an efficient 3 stage charging system. If so you should be able to recharge your battery bank within 2 or 3 of days of continuous generator use.

[Unyalli]

jerryspoolman wrote:
Don't waste your money on a large inverter unless you have a means to recharge it.

Why would I attempt to recharge an inverter? How would I?

- Jeff

[Cheryl_B]

Yeah, I've pretty much been talked out of every idea I've ever had and asked about on this forum. Thanks, though. No sarcasm intended.

[jerryspoolman]

Don't waste your money on a large inverter unless you have a means to recharge it. I bought a refurbished 2500 watt Xantrex (online)and (3) 12volt 8D AGM batteries and boondock. The inverter has a 100 amp charging ability. It takes about an hour to recharge every morning when camping. I use a 2K Honda for the recharging, I use the generator for the Microwave. If you have access to the AC wiring in the RV; install the inverter after the AC, water heater and other high power appliances.
I've been using this setup for over 12 years and the batteries are still holding up. The inverter keeps the batteries charged when parked.

[Sam_Spade]

2oldman wrote:

Cheryl_B wrote:

Maybe this inverter is more powerful than I need, but I always heard that to run the a/c, it needs to be 3000. I would like to run the a/c when I need it.

Forget that. Without a boatload of batteries that isn't feasible.

Knowing that you are a "full timer" puts a slightly different spin on this discussion.

Running an air conditioner through an inverter is a fools errand. Sorry but it just IS. Too many batteries required and then......how will you recharge them; use the power from the campground pole.....well, then the whole discussion is kind of moot.

I think you are about to spend a **** load of money, waste a LOT of time and create a HUGE headache for yourself.

Your time would MUCH better spent looking for a cheaper place to park.

AND....since you had a gen before, you already should be equipped for that. In a class C, most gen's are located in one of the "basement" storage compartments and if you pay a little attention to ventillation (including leaving the door open and having an exhaust extension) you should be able run it without removing it.

Overall.....your proposed "solution" is worse than the "disease"; MUCH WORSE.

[landyacht318]

What other loads do you require?

Powering an Airconditrioner off batyteries is a by no means impossible, but is unlikely without gobs of battery and recharging power.

Alternator recharging is limited by the alternator to house battery circuit and its resistance, and the Vehicles voltage regulator, which basically controls the output of the alternator. Vehicles VRs rarely seek and hold a higher voltgae for very long and voltgae is electrical pressure, the higher the pressure the more amps flow, up to a point.

Basically relying ONLY on the alternator, well it is unlikely many hours of driving each day will return the battery anywhere near 100% state of charge, and for a lead acid battery to live a respectable lifespan it needs to get back to a true 100% every so often. The longer it goes without the 100% recharge, the longer it will then take to refill the battery to some percentage of its as new capacity. A lead acid battery is like a gas tank which keeps getting smaller the more time it spends less than full.

So employ any and all chartging sources whenever possible to get the battery to as high a state of charge as practical, or accept lesser battery longevity.

Cycling a battery to 50% state fo charge, with a high amp charging source early morning, can get the battery bank quickly to 80% state of charge, but 80% to 100% state of charge is likely going to take 3.5 more hours at the absolute minimum, and that is with the battery held at a mid 14 voltage for that 3.5+ hours.

Solar is great, when combined with a higher amp charging source early in the morning when batteries are most depleted and can accept the most 'bulk;' current from a high amp charging source, whether it be a well wired fast spinning alternator, or a high amp converter seeking 14.4+ volts powered either by thge grid or a generator capable of supporting the high amp plug in charging source.

[azrving]

SidecarFlip wrote:
I do know one thing for sure and that is my next TC (if I buy another one) will not have a forced air furnace. It will have a Wave heater than consumes no electricity at all. A Wvae heater and a casette toilet and no black tank to deal with and probably a Danfoss Compressor fridge too. Between the LED lighting (which I already have, every light, inside and out is LED) and the other items, my electricity needs will be very low.

Do you use the wave while sleeping? I looked at the wave and the cat platinum. The Cat uses a couple amps to start ignition and half an amp or so to run. It's vented through pvc so it's high efficiency too.

[SidecarFlip]

I do know one thing for sure and that is my next TC (if I buy another one) will not have a forced air furnace. It will have a Wave heater than consumes no electricity at all. A Wvae heater and a casette toilet and no black tank to deal with and probably a Danfoss Compressor fridge too. Between the LED lighting (which I already have, every light, inside and out is LED) and the other items, my electricity needs will be very low.

[azrving]

If there are other items that you want to power with the generator like hair dryer, toaster, micro etc some people will try to do everything on the generator during the morning and then possibly run it again in the evening. During generator time an upgraded converter can be putting the big amps back in the battery. When the genny time is over and the sun is higher in the sky the solar can do it's work.