MPP LV2424 or not?

[prduke]

I am looking for a solar back up system. Not a full house. Just something that can run a fridge, freezer, sump pump, fireplace insert, couple lights, maybe a hot plate, etc to help with power outages. I have seen some videos on the LV2424 and love the portable set ups I have seen. I also like the "all in one", so I think a newbie like me won't have to worry as much with different fuses, busbars, can charge the batteries via normal outlet, etc. Couple of questions that I would like to defer to those that are more in the know.
I assume i need to try to stick to half the inverter rating when powering items?
Is the LV2424 good for what I need? ie...is the 2400 watt inverter enough? (am i to only run at 50%)
Is something like the Growatt better with a 3000 watt inverter?
ShopSolar.com has the LV2424 combo for $3500...comes with all things needed (cables, fuse, 2 200AH 12 volt batteries, 800 watt panels, etc)...is that a good deal vs piecing things together myself?
Should I look at other "all in ones"?

Thanks

 

[Mattb4]

You could probably power the items on your list a few at a time but it would be easy to overdo that inverter if several of them are running and you get a high starting surge on a heavy load item. You will want to know what each item you intend to power has in the way of start current, running current and also time in operation. You will need this to properly size your solar and battery needs.

Kit prices are often more expensive than if you price components yourself. Also the decisions the supplier of the kit makes may or may not fit your needs. However by looking at what is provided can help you in creating your own kit.

If you stick to a 24v setup I would recommend a 3kw AIO. Keep in mind the specifications for solar input voltage and amperage, battery charging current and max AC output.

 

[prduke]

You could probably power the items on your list a few at a time but it would be easy to overdo that inverter if several of them are running and you get a high starting surge on a heavy load item. You will want to know what each item you intend to power has in the way of start current, running current and also time in operation. You will need this to properly size your solar and battery needs.

Kit prices are often more expensive than if you price components yourself. Also the decisions the supplier of the kit makes may or may not fit your needs. However by looking at what is provided can help you in creating your own kit.

If you stick to a 24v setup I would recommend a 3kw AIO. Keep in mind the specifications for solar input voltage and amperage, battery charging current and max AC output.

Thank you. I am new to this and these all in ones look great. Throw on a breaker, add some outlets, and I am good. I know...I am simplifying it a bit. But versus "normal" inverters, this is the way to go. Thank you for your response.

 

[iwasforcedtopickausername]

All in ones often use a lot of power with the inverter. The 2424 I'm not familiar with, though.

Are those AGM batteries or lifepo4? I'm guessing you could do a better kit shopping around. 24V might be the right size to be working with, though.

Do you know how you want to mount your panels? That's often one of the hardest parts.

 

[timselectric]

If you think you might possibly want to expand (and you probably will). I would suggest that you go ahead and choose a 48v system. Or build your own battery from individual cells. So that you can reconfigure them from 24v to 48v later. Nothing sucks more than not being able to use something that you paid good money for.

 

[OffGridForGood]

I am looking for a solar back up system. Not a full house. Just something that can run a fridge, freezer, sump pump, fireplace insert, couple lights, maybe a hot plate, etc to help with power outages.

I may as well be the one to tell you, as we are all thinking it as we read this posting:
Start with a list of items (loads) and list what these require to: start, run and what they consume in 24hours (ie fridge to start up may draw 10A x 120vac, running after start up may draw 3A 120vac, and cycling for 24 hrs may consume 1800 watts, 1.8kW.
Make a spreadsheet - lots on the forum here to get you started.
Items like a fridge that cycle are hard to know the 24hr consumption, unless you have a kil-o-watt (look it up) or you can use energy guides or other resources that list typical houshold loads.
Looking at the piece of equipment first, instead of the loads first is cart-before-the-horse stuff.
Another good thing to know is a budget,
and for members to assist you - knowing what general part of the globe you inhabit is of great help too.
Welcome to Solar, it is a journey not a destination.

 

[OM617YOTA]

I have two LV2424's for split-phase use. No experience with them yet, as my system build is still in progress. Wish I'd gone to 48v, though. I'd have a more capable, more expandable/future proof, and likely less expensive system.

 

[OM617YOTA]

Items like a fridge that cycle are hard to know the 24hr consumption, unless you have a kil-o-watt (look it up)

This is really good advice. To spec in my system, I measured my fridge and freezer's consumption for an entire week, during the middle of summer, then divided by 7 to get 24 hour usage. This was worst case scenario, and would include any defrost cycles.

 

[OffGridForGood]

I have two LV2424's for split-phase use. No experience with them yet, as my system build is still in progress. Wish I'd gone to 48v, though. I'd have a more capable, more expandable/future proof, and likely less expensive system.

I would suggest that you consider: repurpose them (RV?), or put them up for sale, rather than proceeding to purchase additional parts/equipment etcto build out a full system using the 24 volt AIO "just becasue you already own them" if really your system should be based on other equipment to properly and efficiently serve the loads you wish to power long term.
I suspect (based on the recent back log) that you can easily sell the LV2424's for about what you paid, and reinvest that money into the equipment you wish you had started with.
I guess in short, don't feel Stuck with 24volt, there are options to move to 48V Ditto if you have 24V batteries, these can be sold off, or put in series (maybe - depends on a few details).

 

[iwasforcedtopickausername]

The rule of thumb is keeping it at (or preferably) under 2,400 watts (edit: I mean 100 amps, which is 2,400 watts at 24V). If you'll never need more than 2,400 watts (perhaps a surge 2,400 watts), then 24V may be fine.

There are advantages to 24V over 48V. I have a thread about this here: https://diysolarforum.com/threads/12v-vs-24v-vs-48v-24v-sweet-spot.49740/

That said, if you *might* expand later, then going for 48V could make sense. But based on what you described, 24V does sound adequate.

 

[OffGridForGood]

The rule of thumb is keeping it at (or preferably) under 2,400 watts.

Not a bad starting point, so again, the OP needs to start with the loads they have, and do the math.
then they can look at the What if's - expansion and make a decision and design from this point.
If you return to how they first opened this thread, 'I saw this vid, and I bought product x, now I am trying to figure out what else I need to make this all work' - we see this quite often, and it is understandable, but backwards. A system needs to be based on what loads it will be required to supply, both instantaneous start up loads and 24 hr consumption capacity. The OP noted "just a fridge, freezer, fireplace insert, sump pump maybe a hot plate"
Some of these, say the fridge will use upwards of 1.8kW per 24hrs alone, and many fridges have surprisingly high in-rush on start. Now we add his freezer, sump pump, fireplace insert (maybe this is gas and needs only low power to run?) and a hot plate, I feel he will need a larger system than he currently realizes just to handle starting some of these loads. This doesn't mean it can't be done with 24VDC but it starts to make 48VDC worth considering, especially if he is already thinking of future additional loads.
Full Disclosure: I have a 48V 12kW system for my shop and home critical loads, and a separte and portable 24V 3kW system for a cabin, RV, Greenhouse and odd jobs far away from stationary power sources. Each has it's place.

 

[Jim Burrow]

I've been using the LV2424 now for almost 2 years with 6 solar panels and one 24v, 100 ah lithium battery. I have a double pole double throw switch that lets me connect the ac input to the LV2424 from either my utility company or direct from my gas generator. (Where I live, we lose utility power a lot in the summertime.

I have my electrical box (sub panel) split into where one side is connected to the Utility 24/7 and the other side is connected to the Controller output. So, all the appliances are connected to the utility 24/7 and the rest of the house to the controller. The controller has no problem running two refrigerators, but not the microwave and some other appliances at the same time.

But the way my home wiring we done (It's a manufactured home in a mobile park) I have one circuit branch that somehow bleeds over to the other side of the panel. However, everything does work although I feel it is not totally safe.
So, I would like to sell my LV2424 and get a controller that has 120/240 slit phase and that way I don't have to screw around with the subpanel and house internal wiring. With a 120/240 slit phase controller, I will be totally safe electrically and personally.

The other limit I have with my LV2424 is that it goes into overload and powers itself off for 45 seconds and then powers back on any time the ac output from the control exceeds 22 amps. Again, a problem due to the home internal screwed up wiring.

Anyway, anyone living in California interested in a LV2424, I would like to sell mine so I can get a controller more suited for my home wiring.

 

[OffGridForGood]

I assume i need to try to stick to half the inverter rating when powering items

Best not to plan a system that would be using any inverter at 100% 'all the time' - and you see the comment from Jim Burrow related to 120/240 loads.
That said, the inverters have some allowance for overload, typical MPP Solar (high frequency) is x1.5 for five seconds (think of the starting energy when your fridge/sump pump cycles on) all the loads listed in your OP are short term running (the fridge and sump cycle on and off, the hot plate is used for meals then off all day, lights at night etc). The issues arise when say by chance your fridge and sump pump try to both start at the exact same time. This can happen if the system was off, then turned on while both pieces of equipment were waiting to restart. The in-rush (starting current) of the two items together are likely to overload the available supply and the invertor or the battery will switch off to protect the system.
So if you pay attention to the loads, and make sure things 'take turns' running you can make a small system work even with some bigger loads.

 

[Mattb4]

Best not to plan a system that would be using any inverter at 100% 'all the time' - ...

This is a good practice to follow on any alternative power source. My practice is to down rate the specs by 75% for max load. Thus a 2400w rated inverter or portable generator should be expected to deliver 1800w reliably. 3kw rating is a sweet spot for most loads that you feed a normal 15-20a household circuit.

Manufacturers of consumer electric devices always give a max rating that a unit could deliver if you push it to the limit, but only for a short while. At least the honest ones do. The less than honest (Chinese) give a max rating you can achieve if the moon is full and you have offered proper sacrifice to the gods.

 

[OffGridForGood]

I would like to sell my LV2424

FYI - Jim
If you repost this in the Forum DIY Marketplace under Inverters, it will be seen by members looking to purchase. May be a good place to look for your new Inverter too.
BTW, an easy 120/240 is the MPP 6048 (I have two, but even just one outputs both 120 and 240) the down side of this inverter is standby consumption, which is best overcome with extra panels if you have the space for them.
Robert.

 

[OM617YOTA]

I would suggest that you consider: repurpose them (RV?), or put them up for sale, rather than proceeding to purchase additional parts/equipment etcto build out a full system using the 24 volt AIO "just becasue you already own them" if really your system should be based on other equipment to properly and efficiently serve the loads you wish to power long term.
I suspect (based on the recent back log) that you can easily sell the LV2424's for about what you paid, and reinvest that money into the equipment you wish you had started with.
I guess in short, don't feel Stuck with 24volt, there are options to move to 48V Ditto if you have 24V batteries, these can be sold off, or put in series (maybe - depends on a few details).

I definitely considered this.

In the end, I decided to continue as planned. The system will 100% handle what I've spec'd it for and the only things left to buy are hinges and a latch for the enclosed trailer door, and air vents. It's taken forever to build as it is, I'm not going to add more delays by changing things up now.

 

[OffGridForGood]

I definitely considered this.

In the end, I decided to continue as planned.

Excellent, It would be interesting to see a follow up posting on how it all works out.
In the end, if it does what you need, it is good.
Even if you(or any of us) changed your mind down the road, I expect it will not be difficult to sell off a working system on line.

 

[prduke]

All...thank you. This is all great info. Like I said, I am new and just trying to gather info and understand. THANK YOU for not treating me like a dumb newbie. You may have thought it, but you didn't say it. Ha!
As stated, this would be a portable system and not tied into our house. I did not give enough details. Those that suggested a kill a watt...great idea. And I have run those numbers. I understand the start up surges. My only "hope" is that they don't all kick on at once. =-) I assume that if that happens, it will trip a breaker (plan on using this) and then I can reset it.
Fridge and freezer take 175 and 195 watts...note...for example, the fridge per the killawatt took 1.08 Kilowatts for 23 hours. So in that 23 hours, it ran at 49 watts hours per hour. Fireplace insert (firewood) takes 65 watts, sump pump at 900 watts but only runs for 5 seconds, Hot plate at 1000 watts. Granted...I could not run freezer and insert while cooking up some hamburger helper.
This is for power out / survival mode...not going to be running TV, ceiling fans, play station, oven, dvd player, etc. =-)
Again...huge help and I will re-read the postings and digest more.

 

[OM617YOTA]

Day 2 without power, you'll be wanting to run the TV, modem, and wifi router.

I originally spec'd in my system for three 410w panels. I'm actually quite thankful that when I went to buy, it was a 4 panel min. I suspect we won't have any trouble using the extra power.

 

[timselectric]

Nobody ever complains about having too much power. (My goal is to be in that position)