inverter/generator or AIO recommendation

[Nimrod5]

I have an off grid 40 in northern MN. I was given 1600 watts of panels and a Midnite Solar Kid charge controller. I need to buy a 48 volt battery bank and an inverter/charger or an AIO.

The biggest load I would like to run is a stick welder that runs fine on 240 volts and 20 amps of grid power. I do plan to add more panels and, if necessary, another charge controller later so I will buy a bigger battery bank and inverter/charger than I need at first.. I may do LiFePo4 batteries if I can put them in a root cellar so they don't freeze.

I have looked at inverter/generators and am seriously considering the Schneider SW 4048. It is a low frequency inverter that can handle large surge loads for a long time relative to high frequency ones. It has 120/240 volt output. It is one of the better ones for durability. The thing that sets it apart from the others is the way it handles a generator input. It does not require a 240 volt genny. It will take a 120 volt genny input and charge the batteries and/or add the genny input to the inverter output. If the inverter out put is 240 volts it will split the genny's 120 volt output and add add half the genny's output the each leg of the inverter's output. Correct me if I am wrong. I will need to connect a genny in the winter and have a 120 volt one.

All the other inverter/generators and AIOs that have split phase output require a 240 volt generator. I would have to buy a new generator. Anybody know of another inverter/generator or AIO that handles a 120 volt genny? Any comments for or against the Schneider SW 4048?

I do realize that if I go with the SW 4048 I will need to buy another charge controller when I add to the battery bank and panels while an AIO now won't need another charge controller.

 

[sunshine_eggo]

Inverter/generator is usually referenced as an inverter/charger.

It has 120/240 volt output. It is one of the better ones for durability. The thing that sets it apart from the others is the way it handles a generator input. It does not require a 240 volt genny. It will take a 120 volt genny input and charge the batteries and/or add the genny input to the inverter output.

This part does not sound right. Victron is the only inverter I know of that can boost input AC (generator or grid) to supplement weak AC input.

ALL inverter/chargers pass through the incoming AC power to loads and charge with the surplus. Inverter/chargers can do both... but not at the same time.

If the inverter out put is 240 volts it will split the genny's 120 volt output and add add half the genny's output the each leg of the inverter's output. Correct me if I am wrong. I will need to connect a genny in the winter and have a 120 volt one.

I don't know about the schneider specifically, but this is more common on the higher quality units.

All the other inverter/generators and AIOs that have split phase output require a 240 volt generator. I would have to buy a new generator. Anybody know of another inverter/generator or AIO that handles a 120 volt genny? Any comments for or against the Schneider SW 4048?

And many of the AiO don't operate reliably on anything but an inverter generator.

I do realize that if I go with the SW 4048 I will need to buy another charge controller when I add to the battery bank and panels while an AIO now won't need another charge controller.

Magnum MS4448PAE will do the same.

Dual Victrons configured for split phase can do the same.

FWIW, split phase gennys are cheap. My $450 Predator works great.

 

[Nimrod5]

This part does not sound right. Victron is the only inverter I know of that can boost input AC (generator or grid) to supplement weak AC input.

ALL inverter/chargers pass through the incoming AC power to loads and charge with the surplus. Inverter/chargers can do both... but not at the same time.

From the Schneider SW brochure

The Conext SW is the solution of choice
Conext SW inverter/charger features
•
The integrated auto-transformer allows the use of an on-site single phase (120Vac) generator to provide input power to the Conext SW inverter and create a split phase output power (120/240Vac North America only).
•
Generator support allows power to be automatically drawn from the batteries to assist a small efficient AC generator to support heavy loads.

Am I reading this right? I think this backs up what I think it will do. What's the Victron model number?


I don't know about the schneider specifically, but this is more common on the higher quality units.

What units?


And many of the AiO don't operate reliably on anything but an inverter generator.

My genny is a 3500 watt inverter genny.

Thanks for the input. You gave me a couple more things to consider.

 

[Norwasian]

If your welder requires 240-volt, 20-amp input to operate, that's about 5 kw of power (volts x amps = watts). You should be looking for a 5kw or better inverter. I think the welder might operate at lower amperages as well if it is not using its highest settings, e.g. if it is, say, a 160-amp inverter welder, and you set the heat at 90-amps, it might use considerably fewer watts than if running at its full power at 160-amps for welding. It is not clear to me whether your welder is single-phase, or uses two phases at 120VAC each to reach 240 volts. If it is using two phases, you will need an inverter setup that produces both phases to match its requirements. Some inverters do this natively, as I understand, while others require a second unit running in parallel. I'm in Thailand where everything is 230-volts on a single phase, so it's virtually a non-issue here.

 

[MrThisIsME]

single-phase, or uses two phases at 120VAC each to reach 240 volts.

He mentioned Minnesota =- so split phase 240v.

 

[sunshine_eggo]

Generator support allows power to be automatically drawn from the batteries to assist a small efficient AC generator to support heavy loads.

Am I reading this right? I think this backs up what I think it will do. What's the Victron model number?

Agree. That sounds just like Victron PowerAssist.

 

[Steve_S]

MOST IMPORTANT ! BUY NOTHING TILL YOU HAVE A PLAN !!!

1) 240VAC/20A = Minimum of 4800W, and we always Round Up so say 5000W "at least" but remember there is a BIG Surge when you hit the trigger and that can be up to 3X or 15,000W. It does depend on type of Welder but they are not designed to be "pleasant" in the efficiency dept.

2) Do NOT even consider a High Frequency Inverter/Charger with such intense loading, you will need a Low Frequency unit that can take abuse & not get cooked. HF also only handles 2X Surge while Low Frequency systems can handle 3X surge. More info below:

Inversion Methods Explained: High Frequency vs Low Frequency | Magnum Dimensions

Understand the difference between high frequency and low frequency inverters with this quick article.

www.magnum-dimensions.com

3) The Midnite Kidd is a Great Controller but it is VERY LIMITED ! I've put in a few, they Max out at around 800W Input and only produce 20A +/-. Great for an RV or small cabin or so but not to run anything serious longterm. You will need a better SCC (Solar Charge Controller) that can deliver the Voltage & Amperage to charge your battery system. A single 48V/100AH LFP Battery has 5120Wh or 5.1kWh of energy and multiple Battery acks can be set in Parallel to increase storage capacity. LFP BONUS ! You can add battery packs over time without negative consequences, LFP is NOT like Flooded Lead Acid.

4) Battery System: Without a doubt, 48V is the way to go for 240V Systems and heavy load handling like welders and such. The sizing of that battery bank MUST be determined, to figure out how much Solar Panel & SCC Sizing is needed to charge the battery system. Until you KNOW What your Daily Power consumption will be for the system AND how many days reserve you want "On Hand" before needing to run a genset is also a big factor.

5) AIO's (All In Ones) which have Solar Controller(s), Inverter & Charger built into 1 unit are very convenient and can simplify installation may NOT BE Optimal depending on your Needs & Wants. Note that Most AIO's are HF (High Frequency) which further complicates a search for a solution.

Schneider is GOOD reliable & tough as nails BUT getting "Long in the tooth" which is both Good & Bad... Good cause they are reliable & solid with a long record, support is pretty good too... Bad part is they are dated to a point... the Software & Firmware is kept up to date though, so it's not really "bad" as such.

With such an application, you're headed in the right direction by looking at Tier-1 Products (you DO get what you pay for !). Schneider, Victron(*1), Midnite (non-DIY series), Outback, Dyey(*2), Magnum.
(*1) I strongly recommend Victron, Long Standing Excellent Support (across the board) and has an excellent Eco-system where ALL Victon gear can be interconnected & managed/monitored with software (phone/pc and/or System Display with Cerbo)
(*2) Dye is a Good Company with HF & LF but there is "peculiarities" that have come out recently and there is contention & issues... I do not follow that but does raise some questions. Quality & Support stuff.

Generators:
Ahh a gotcha that get's some. Depending in "Charger" system & Battery bank setup, some can take 120V or 240V. That is a decision to be made once you "Have a Plan in place" and know what you will need to power. There is a GOTCHA !!! When you get into Solar & Battery powered system, it is Very Seriously Suggested that you use an Inverter Generator that produces Clean Pure Sine power ! Construction Gennies are typically MOD Sine and the Frequency (Hz) and Voltage tends to float and that will pass through to your home while in use. This is NOT good for fine electronics & motors. Many Inverter/Chargers will NOT Qualify that power source if they are too far out of spec (common). Lastly, it is important to know, that an Inverter/Charger WILL NOT Clean up the incoming power source, they can't. Fortunately there are now some really good Inverter Generators for a fair / reasonable price, I use Champion Gennies (have for over a decade) without any issues (granted I am religious about oil changes (synthetic only) and maintenance. I use a new Champion 4650W Dual Fuel Genny which I don't have to run about 50% capacity to charge (use 2600-2700W) leaving ample room for Passthrough surge draws and letting it run in Eco Mode while charging (makes a Huge Diff).

For better information from us, please provide Make & Model of any equipment you have (Solar Panels & Hardware) presently. Links to products you may have bought. PLEASE DO NOT BUY ANYTHING TILL YOU HAVE A SOLID PLAN ! I also MUST SAY, it takes time to learn & understand and NEVER EVER Make Assumptions (they're great for making an ass out of oneself).

In closing a few things to note for consideration.
- It is Much Cheaper to conserve power that it is to generate & store ! Efficient appliances & devices and cut the extra overhead. Old Appliances like Grandma's Fridge you inherited that's in the garage to keep the beer cold are usually energy pigs... you'd be surprised ! Cookstoves and such are another Big Example of power wasters.

- Whatever power consumption you come up with will ALWAYS BE SHORT ! No one ever estimates their consumption - part of the "taken for granted" thing everyone does. Then of course we are always adding some new-fangled gadget that needs power. This in turn demands 2 Things, A) Plan for expansion at a future date (more Batt or Panel or Inverter) so design accordingly leaving provision to do so. This even includes wiring for example. If you are building a system to support say, 240V/50A then wire for the Next Size Up which you may consider as 240V/100A. In other words, don't lock yourself in at a lower rate which you may think you won;t go beyond. Wanna require (trench & pull-replace wire) etc... also keep in mind that the cost of copper today will be considered cheap in 5 years. (up 400% in price in past 7 yrs) No Chit !!

- Many "devices" like Well Pumps, Big A/C, etc should have Soft-Start Modules to reduce the Demand Surge on start-up to make it easier (gentler) on the inverter system. For example a Well Pump can easily draw 3X it's max rating for a start surge. Compressors are also nasty.

- A BIGGY ! There are some things that you CAN be frugal (aka cheap) on but some that you can't ! Fuses, Breakers are something you can NEVER Cheap out on ! They can save YOU & your gear - not a compromise point. 1 Fellow here just lost his house due to a cheap Melted Fuse that arced.

Hope it helps, Good Luck.