24V Inverter

Oonrahnjay · February 18, 2015, 08:52:52 AM

A couple of questions regarding a fairly-large-capacity (3.5K -- 4K Watt) 24V inverter .....

1) In your opinion, what's the best inverter like this made and available in the market, price no object?

2) If you had to balance price and "best", what would your choice be?

Thanks for your experience and opinions on this. BH NC USA

bevans6 · February 18, 2015, 09:34:47 AM

I researched this for a long time and found that the Magnum Hybrid 4000 watt inverter was the right one to have for RV use. The MSH4024 is designed for mobile or home use, has a very good battery charger, can pass through or augment mains power, has a good remote control, battery temp sensor, can start a generator. There are more expensive units available, but I saw none that offered greater value. I bought the MS4024, without the hybrid capability, because it was significantly cheaper at the time, and my dealer didn't have stock of the MSH anyway. One reason I chose Magnum was the word on the street was their factory support was good.

Brian

digesterman · February 18, 2015, 10:26:17 AM

Look at the outbacks, top quality, put two in and you can have 220

Jon · February 18, 2015, 10:29:01 AM

Any of the pure sine wave inverter chargers of today are excellent. Both of the ones being used in expensive conversions were mentioned previously. I have a pair of OUtback and they have been great.

bevans6 · February 18, 2015, 10:34:32 AM

Outback was my second choice, the difference being the dealer I picked had the Magnum as their "house" brand. Little to choose from between them, they are both top shelf.

eagle19952 · February 18, 2015, 10:35:24 AM

Are pure sine wave inverters really necessary ? or are they just the cats meow ?
i have never regretted not having a pure sine wave.
the Trace models and early Xantrex models have always done the job.

bevans6 · February 18, 2015, 10:56:42 AM

No, they're not really necessary for a number of applications typical to rv use, but they are better for everything that depends on a sine wave to function more efficiently. The things that are affected least by a square wave inverter are things that are purely resistive loads, like a light bulb or a heating element. Things that are affected a lot more are things that require a sine wave to operate efficiently, like an electric motor or a microwave oven, or anything with a transformer in it. some things just operate at reduced power, other things like motors actually fight the incoming square wave power and run hotter, and in microwaves the magnetron tube and it's transformer can be damaged. Things like battery chargers can be ruined pretty quickly, other things like TV's or things with multi-voltage power supplies could care less. Anything that depends on detecting the zero crossing point of the AC signal for timing, like a clock, won't work right.

Pure sine is just better for everything. They are getting a lot cheaper, I have a 1,000 watt cheapie model that I paid less than $200 for. For those that are fond of arcane technical trivia, a pure sine wave inverter actually puts out something called a pulse width modulated square wave signal that is fairly high frequency (around 20Khz), the average voltage of which mimics the voltage of an actual sine wave from a generator, and so the signal, as soon as it gets a little filtering, looks exactly like a sine wave, but is made up of a whole bunch of tiny little square wave pulses.

Brian

bobofthenorth · February 18, 2015, 11:15:00 AM

We've had 2 Heart Freedom 25s which are (antique) MSW inverters. They have both been excellent and have run absolutely everything we have ever hooked up to them with one major exception - electric blankets/mattress pads. I don't think the pad itself cared about the power source but the controllers are another story altogether. We had one which would start blinking whenever it saw inverter power but would recover if you unplugged it and then fed it mains power. The other one died instantly even though it was nominally "off" when it saw the inverter power. Like a complete moron I managed to do that twice with the same model of blanket. As a result of that we now have an electric blanket with fully analog controls - it was extremely hard to find one but they are out there.

Other than the blanket situation we've run computer bricks, wall warts, fridges, freezers, air compressors, microwaves, stoves, coffee pots, televisions, DVRs - literally everything through the inverter. We've been tied to an abandoned dock for a week now alternating between generator and inverter power and we pay absolutely zero attention to what is turned on. As long as the batteries stay above 60% life is good.

Lee Bradley · February 18, 2015, 11:19:07 AM

I have a Trace 4024 (no longer made) that confuses the clock on the microwave. Other than that it runs everything fine including the step-up transformer for the mini-splits. The thing that I really like is it's ability to boost the income AC power. If it is on a 15 amp outlet and the load increases to 40 amps it will make up the difference from the batteries and recharge the batteries when the load drops back under 15 amps. If the load doesn't drop back down before the batteries reach the voltage cut-out, it will start the generator. So far as I know only the Magnum Hybrid 4000 watt has those features of the inverters currently available and it would probably run my clock; not enough for me to upgrade.

eagle19952 · February 18, 2015, 12:42:06 PM

Truth is the older Traces were advertised as a modified wave, why ? because (as I was told) there is no inverter that puts out an exact replication of a "pure" sine wave .

Show me an oscilloscope of a "pure" sine wave, produced by an inverter of any design/manufacture, I have not seen it.

Some square waves are better than others.

I have not lost any devices yet.

Oonrahnjay · February 18, 2015, 12:48:32 PM

Quote from: Lee Bradley on February 18, 2015, 11:19:07 AMI have a Trace 4024 (no longer made) that confuses the clock on the microwave. Other than that it runs everything fine including the step-up transformer for the mini-splits. The thing that I really like is it's ability to boost the income AC power. If it is on a 15 amp outlet and the load increases to 40 amps it will make up the difference from the batteries and recharge the batteries when the load drops back under 15 amps. If the load doesn't drop back down before the batteries reach the voltage cut-out, it will start the generator. So far as I know only the Magnum Hybrid 4000 watt has those features of the inverters currently available and it would probably run my clock; not enough for me to upgrade.

I currently have an Outback that does not do the income boost and I find it a PITA to unplug, fire up the generator, run a load, then reverse the process when the load is completed. If I try to pull more than the power I've specified, the whole thing (inverter, charger, etc.) just crumples. The "make up the difference" thing is what I thought that I was getting with the Outback and didn't and that has really disappointed me.
Reason I ask (first post) is the I'm going to a new engine and 12V will not be available in the amount needed to run an inverter. Since I need to go to a 24V inverter for this and other reasons, I wanted to go to a good one.
Thanks for all the good info and experience. BH NC USA

bevans6 · February 18, 2015, 02:39:01 PM

edit out, I linked the wrong page.

I think this you-tube video has live screen shots of pure sine wave inverter output. I didn't watch the whole thing, I am on a bandwidth limited internet connection.

https://www.youtube.com/watch?v=Koc9rR4ad4Q

All the better stuff I have found is in PDF format, and I don't know how to link PDF's

brian

eagle19952 · February 18, 2015, 04:04:33 PM

That's all well and good, but I am comparing high quality PSW vs high quality MSW.... still not convinced, i have owned both and havenot suffered any losses or noticeable deterioration of end uses. the difference can be $1000.00 plus ...

Quote from: bevans6 on February 18, 2015, 02:39:01 PM
edit out, I linked the wrong page.

I think this you-tube video has live screen shots of pure sine wave inverter output. I didn't watch the whole thing, I am on a bandwidth limited internet connection.

https://www.youtube.com/watch?v=Koc9rR4ad4Q

All the better stuff I have found is in PDF format, and I don't know how to link PDF's

brian

bevans6 · February 18, 2015, 04:10:32 PM

What it boils down to is if you have high quality older MSW stuff that is working for you and you are happy, stick with it. There are no high quality MSW inverter chargers made today, so if you are buying new, buy a great current, modern pure sine unit. I wouldn't change out something that was working either.

Brian

eagle19952 · February 18, 2015, 04:14:22 PM

Agreed.

,
having said that, if I were on a budget and found an old TRACE for 1/3 the cost of a Magnum...well I'd certainly consider the Trace. It is also a bit easier to decide if you know what your looking at. (age wear and tear and abuse).

Quote from: bevans6 on February 18, 2015, 04:10:32 PM
What it boils down to is if you have high quality older MSW stuff that is working for you and you are happy, stick with it. There are no high quality MSW inverter chargers made today, so if you are buying new, buy a great current, modern pure sine unit. I wouldn't change out something that was working either.

Brian