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diy solar

Help with choosing a inverter for a portable diy solar generator

dahluwalia

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Joined
Apr 24, 2023
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62
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maryland
So I wanting to build a movable solar generator .I keep going around and around about how , and what I really need or want. I wanted to be some what expandable (but maybe thats holding me back) I bought 2 100ah powerurus lifepo4 batteries as a start. I' looking to be able to wheel it around the house at first for when power goes out usally less than a day but want to use if longer. I don't have panels yet but probably couldnt do more than 4 and they would probly need to movable no roof. I need to run a cpap . would like to run router tv or laptop instead of tv,charge phone run a few lights a microwave (just a few minutes)a refridge ,but not all at one time . I dont mind cycling the refridge every few hours if needed . some day I'd like to be able to hook into my house to run these things with out extension cords.I'm looking at 2000 watt inverters .I'm thinking the all in ones have too much idle consumption for a small backup.? But not sure if you could plug a stand alone inverter to the house /manual transfer box or however you tie into house.? And also looking at chargers and controllers , and ideals on panels or even should I go 24v . To much questions . Thanks for any and all help
 
Why "movable"? Are you going to move it to your devices/appliances when needed?
If so, get a separate charger, and just move the batteries and inverter.

Otherwise, install a critical loads panel, and use the breakers to control which circuits get power.
 
Take a look at XIJIA (CNSPOWER) on Aliexpress. Andy from Off-Grid-Garage has a 48v model. I have thier 12v model, 1500w.
It's pretty compact (although the 24v 2000w might be a bit larger). Idle consumption of my 12v 1500w is between 7-15w (can't recall exactly). Thats pretty low compared to all-in-ones (typically 50w and above).
 
Find an MPP Solar 24v AIO inverter, and slap it together with your two existing (12v?) 100ah batteries, in 24v configuration, and mount it all on a hand-truck. Add the appropriate fuses & cables. You can research the 24v inverters at mppsolar.com, and see if their off-grid model, or some other model, works for you. Plenty of youtube vids on these diy "hand-truck" solar generators.

For output power, hook up a decent power strip to the AC out of the inverter. Use the grid AC to recharge the batteries via shore power (AC in on the inverter). Run appropriate cabling from outdoor panel(s) to the inverter's mppt connections, for daytime charging.

For a grid outage, the higher idle draw of the AIO inverters won't eat your lunch for a short outage window, but use the online solar calculator pages to verify all the appliances you intend to run, and add the inverter idle draw as another appliance; you can see how much battery it will consume, and do what-if's for panel sizing, battery-bank capacity, etc. Two such sites are:

1. at this calculator page, enter in each appliance's values (watts, hours/day you want to run it, etc.):
unboundsolar.com/solar-information/offgrid-calculator

2. using numbers from above, fiddle with various entries/components, and you'll see in real-time what your system component (inverter, mppt, panel) sizing is:
altestore.com/store/calculators/off_grid_calculator/

Hope this helps ...
 
Why "movable"? Are you going to move it to your devices/appliances when needed?
If so, get a separate charger, and just move the batteries and inverter.

Otherwise, install a critical loads panel, and use the breakers to control which circuits get power.
I thought I may not be able to afford a electrician yet to the it to my house right away so have to run extension cord s
 
What is the surge current the fridge?
What is the power input rating of the microwave?
 
Find an MPP Solar 24v AIO inverter, and slap it together with your two existing (12v?) 100ah batteries, in 24v configuration, and mount it all on a hand-truck. Add the appropriate fuses & cables. You can research the 24v inverters at mppsolar.com, and see if their off-grid model, or some other model, works for you. Plenty of youtube vids on these diy "hand-truck" solar generators.

For output power, hook up a decent power strip to the AC out of the inverter. Use the grid AC to recharge the batteries via shore power (AC in on the inverter). Run appropriate cabling from outdoor panel(s) to the inverter's mppt connections, for daytime charging.

For a grid outage, the higher idle draw of the AIO inverters won't eat your lunch for a short outage window, but use the online solar calculator pages to verify all the appliances you intend to run, and add the inverter idle draw as another appliance; you can see how much battery it will consume, and do what-if's for panel sizing, battery-bank capacity, etc. Two such sites are:

1. at this calculator page, enter in each appliance's values (watts, hours/day you want to run it, etc.):
unboundsolar.com/solar-information/offgrid-calculator

2. using numbers from above, fiddle with various entries/components, and you'll see in real-time what your system component (inverter, mppt, panel) sizing is:
altestore.com/store/calculators/off_grid_calculator/

Hope this helps ...
Thanks I was wondering if 24 v is better i was worried about idle power. But I guess any way you go there will be idle draw. I guess I can add batteries if I need longer run time. I am wondering what panels required for 24 v
 
The job of a good MPPT controller is to convert PV higher voltage down to lower battery voltage. As long as you can string enough panels to make the controller happy, the kind of panels don't really mattei was thinking of two panels but with 24 will I need more. I can't house roof panels is in the yard i can do. But the house blocks the sun half the day. But if I could do 22 in the front yard and two in the rear it can be summed all day.that is another reason I thought it had to be movable but longer cable will work too?
 
Find an MPP Solar 24v AIO inverter, and slap it together with your two existing (12v?) 100ah batteries, in 24v configuration, and mount it all on a hand-truck. Add the appropriate fuses & cables. You can research the 24v inverters at mppsolar.com, and see if their off-grid model, or some other model, works for you. Plenty of youtube vids on these diy "hand-truck" solar generators.

For output power, hook up a decent power strip to the AC out of the inverter. Use the grid AC to recharge the batteries via shore power (AC in on the inverter). Run appropriate cabling from outdoor panel(s) to the inverter's mppt connections, for daytime charging.

For a grid outage, the higher idle draw of the AIO inverters won't eat your lunch for a short outage window, but use the online solar calculator pages to verify all the appliances you intend to run, and add the inverter idle draw as another appliance; you can see how much battery it will consume, and do what-if's for panel sizing, battery-bank capacity, etc. Two such sites are:

1. at this calculator page, enter in each appliance's values (watts, hours/day you want to run it, etc.):
unboundsolar.com/solar-information/offgrid-calculator

2. using numbers from above, fiddle with various entries/components, and you'll see in real-time what your system component (inverter, mppt, panel) sizing is:
altestore.com/store/calculators/off_grid_calculator/

Hope this helps ...
I saw a mpp 2724lv mr with the built in ac plugs an usb .I know Will liked them . It say 2700 watt max ? is that like 800 watt with a peak 2700? That may be a little low for me ? Could you tie that in to the hose to run a room or so , fridge tv sump pump ? Putting a stip is no big deal I just thought if it aleady has one easier yet
 
I bought my 24v mpp solar aio from watts247.com, as pointed out to me by others ... the one year warranty is kind of cheesy, so I don't expect it will last forever, and at the price I bought it, it is pretty much "disposable" (this is suitable for a hand-truck project). Keep all this in mind for the unit you buy, and if warranty or support is important, consider the vendor and their inverter supporting docs as well as the unit's features.

it shipped fast, and I took it from there to build my solar generator on a hand-truck; I didn't need their "support" ...

for the unit you are looking at, per their datasheet page at:

watts247.com/product/pip-2724lv-mr/

the datasheet seems to indicate a full rating of 2.7kw all the time, and a surge rating of 5.4kw for 5 seconds. You'll want to make sure all your intended loads fit within that 2.7kw, with a bit of room to spare. Things with motors (perhaps your sump pump) might need special care, as in you test it before using (to make sure the mpp inverter can handle it's startup sequence), or you might need a soft start device in front of it.

Don't forget to add the inverter's "idle draw" power as an "appliance", when calculating your loads ... depending on inverter, and on how long you run it for an outage, it could play a role in battery capacity. The calc pages should help figure all this out ...

Hope this helps ...
 
Find an MPP Solar 24v AIO inverter, and slap it together with your two existing (12v?) 100ah batteries, in 24v configuration, and mount it all on a hand-truck. Add the appropriate fuses & cables. You can research the 24v inverters at mppsolar.com, and see if their off-grid model, or some other model, works for you. Plenty of youtube vids on these diy "hand-truck" solar generators.

For output power, hook up a decent power strip to the AC out of the inverter. Use the grid AC to recharge the batteries via shore power (AC in on the inverter). Run appropriate cabling from outdoor panel(s) to the inverter's mppt connections, for daytime charging.

For a grid outage, the higher idle draw of the AIO inverters won't eat your lunch for a short outage window, but use the online solar calculator pages to verify all the appliances you intend to run, and add the inverter idle draw as another appliance; you can see how much battery it will consume, and do what-if's for panel sizing, battery-bank capacity, etc. Two such sites are:

1. at this calculator page, enter in each appliance's values (watts, hours/day you want to run it, etc.):
unboundsolar.com/solar-information/offgrid-calculator

2. using numbers from above, fiddle with various entries/components, and you'll see in real-time what your system component (inverter, mppt, panel) sizing is:
altestore.com/store/calculators/off_grid_calculator/

Hope this helps ...
I think I'm worried about the idle wattage ,Whats the lowest and avrage I can expect
 
I bought my 24v mpp solar aio from watts247.com, as pointed out to me by others ... the one year warranty is kind of cheesy, so I don't expect it will last forever, and at the price I bought it, it is pretty much "disposable" (this is suitable for a hand-truck project). Keep all this in mind for the unit you buy, and if warranty or support is important, consider the vendor and their inverter supporting docs as well as the unit's features.

it shipped fast, and I took it from there to build my solar generator on a hand-truck; I didn't need their "support" ...

for the unit you are looking at, per their datasheet page at:

watts247.com/product/pip-2724lv-mr/

the datasheet seems to indicate a full rating of 2.7kw all the time, and a surge rating of 5.4kw for 5 seconds. You'll want to make sure all your intended loads fit within that 2.7kw, with a bit of room to spare. Things with motors (perhaps your sump pump) might need special care, as in you test it before using (to make sure the mpp inverter can handle it's startup sequence), or you might need a soft start device in front of it.

Don't forget to add the inverter's "idle draw" power as an "appliance", when calculating your loads ... depending on inverter, and on how long you run it for an outage, it could play a role in battery capacity. The calc pages should help figure all this out ...

Hope this helps ...
how does that differ from 2424mpp
 
how does that differ from 2424mpp
the 2724 is not stackable (you can't put two or more in parallel to increase output) but the 2424 is stackable (up to 6 units).
the 2724 has very low input PV max of 600-750W (25Amp) while the 2424 is 80A @145 vdc.
Power saving mode on the 2424 is quite low I believe less than 25W, not sure what the 2724 is, I turn mine off when not needed LOL.

The 2724 is meant to be a small scale portable unit, it has outlets built right into the side of the inverter (plus a couple USB outlets -which are handy too) and the PV inputs are MC-4 connectors, so you just plug in a PV panel or two (up to max 750W) and that is it, ready to use, but not expandable, not able to connect to 4kW of solar or anything large scale. I have this unit for mobility/RV/Cabin and it is awesome for that. It can start and run my 1/3Hp jet pump at the cabin, it can run a jigsaw and brew a coffee with my Keurig, it will run the LED lights in the Greenhouse to get my starters going, and operate the drip irrigation system and controls for the operable windows. I have cut 2x4's with a skillsaw with it, using a 150A capable battery, and I have done quite a lot of work with a 5" angle grinder using the 2724. It is pretty capable for such a low cost and small package. To get the most out of it, you need a battery (ies) capable of 125A output without tripping.
 
I am wondering what panels required for 24 v
forgot to reply to this question in my last post, so here it is:
I had one panel arrive damaged, and got replaced for my main system, so I have this one lone 440W panel that although has a crack in in, works fine. I have set it up a few places as a test, and otherwise use it with my 2724 since it just plugs right into the inverters' MC-4 connections. The Canadian Solar 440W specs:
VOC = 46 vdc
ISC = 9.26A
IMP =8.64
VMP =38.1 vdc

Although the PV panel at 38-46 vdc is much higher voltage than the battery (24-28vdc), the MPP adjusts between the two and charges up the battery appropriately. You need high enough voltage: ie say if you had a 12-18 vdc PV this will be too low and the inverter will not be able to charge up a 24-28vdc battery no matter how much sun you got.
 
I think I'm worried about the idle wattage ,Whats the lowest and avrage I can expect
Since you asked this question, I did a couple tests with my 2724:
Test #1
Powered off, this unit will still charge the battery with a PV panel, so I unplugged the PV to be able to check what power was being consumed by the inverter alone; was 4.75W (0.18A battery was reading 26.4 vdc)
Test #2
unplugged the loads (and PV still unplugged), turned the inverter on, check 120vac was available at the recepticals, checked amps out of the battery with a meter, 0.81A (battery at 26.4 vdc) total of 21.38W while "on" no actual AC loads.

Idle consumption per 24 hours:
Inverter off, would be about 114W per day.
with inverter 'on' actually inverting would be 513W per 24hr day.
 
Well bigger inverter and you would need two more batteries than what you have.
 
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