Recommend a 48V DC to 120/240V inverter charger?

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JAC

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I am in the process of setting up my basic solar system and I am in the market for a 48V DC to 120/240V inverter charger for under $1000. I need to be able to run my water well (240v) in the event of loss of power. At first it will be a non grid tied system but eventually may want to grid tie as we build it up and add more batteries and panels. To begin with, this system will use four 300 watt panels and eight 6volt batteries. I already have the panels, a Midnight Kidd charge controller and about 100 ft of AWG2 copper wire. From what I have gathered this system as it is will be operating at about half it's capability so we plan to add 8 more batteries and 4 more panels in the near future.

Can anyone recommend an inverter/charger for under $1000 ? Maybe one that could switch automatically to grid if need be down the road?
 
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Are you wanting a combined charge controller and inverter or two units?
What is the amp hour capacity of your battery bank?
What is the maximum output of your panels in Volts and Amps?
Are you completely off grid or grid connected?
 
As I said I already have a Midnight Kid charge controller new in the box so I dont think I need a combo charge controller/inverter. Here is a link but i dont think mine has the generator start
http://www.midnitesolar.com/product...e=Software&productCat_ID=43&sortOrder=1&act=p

These are my panels:
https://www.renogy.com/renogy-300-watt-24-volt-monocrystalline-solar-panel/
I bought them a few years ago and they have been stored new in the box. I'm not sure if they are poly or mono panels. I dont see a 300 watt poly panel available so I'm guessing it is these.

As for batteries I have not bought them and it is a good 2 hour drive to the nearest Sams club and I was planning on buying batteries in the next week or so. I donm't know of anywhere closer to buy the batteries as we live in the middle of nowhere. Moved here for that exact reason.
Am I better off with 8 of these 6 volt batteries: https://www.samsclub.com/sams/durac...sel:people-who-viewed-this-item-also-viewed:2

Or 6 of these 8 volt batteries? https://www.samsclub.com/sams/durac...sel:people-who-viewed-this-item-also-viewed:1

I am starting off - offgrid for now but may move to grid tied later on so that has to be part of the plan as well.
 
I can't recommend anything at that price but here are some options. I have not used or researched any of them.

https://www.amazon.com/s/ref=nb_sb_noss?url=search-alias=aps&field-keywords=48V+to+240V+inverter&rh=i:aps,k:48V+to+240V+inverter&ajr=1
While I would love an AIMS unit I think they are pretty much out of my range for what I get out of them in watts. I'm looking at the sungold units but really dont know much about them. I'll have to read reviews and such

Thanks Caribou
 
I found the info on my panels
Optimum Operating Voltage (Vmp) 37.46 V
Optimum Operating Current (Imp) 8.01 A
Open-Circuit Voltage (Voc) 46.12 V
Short-Circuit Current (Isc) 8.56 A

Poly 300 watt panels
 
MNKID Sizing Tool
PV Module Data
Power 300 Watts
VOC 46.12 Volts
VMP 37.46 Volts
ISC 8.22 Amps
IMP 8.01 Amps
VOC Temp Coef % 0.33 C
VMP Temp Coef % 0.45 Amps
Environmental Data
Coldest Ambient Temperature -30 C
Hottest Ambient Temperature 40 C
Nominal Battery Volts 48 Volts
PV Array
Number Of Modules In Series 2
Number Of Parallel Strings 2
Total Modules 4
Rated PV Array Power 1200 Watts
Anticipated Array Power @ 40 C 1119 Watts
Rated PV Array Current 16.02 Amps
Battery Charging Current @ 57.6V 20.8 Amps
VMP (Maximum Power Point Voltage 74.92 Volts
VOC (Open Circuit Voltage) 92.24 Volts
VMP @ -30 C 93.4 Volts
VOC @ -30 C 109 Volts
Charge Controller
Max Operating Voltage 150
Max Non Operating 162
VOC (HyperVOC) @
48V Nominal Bat Voltage
Maximum Number Of 2
Modules In Series
Configuration
Max Allowable Output 30
Current Per KID
Based On This Current
Max Allowable Wattage 1752
Per KID Based On
This Configuration
Present PV Array Wattage 1200
Of This Configuration
Design Check
Max VOC OK
Temp The MNKID Enters HyperVOC -165 C°
Array Power OK
(Wattage)
Classics Required 0.7
NOTE: MidNite Solar recommends a second controller be added after 1.2
WARNING: MidNite Solar makes no representation, warranty or assumption of liability
regarding the use of the String Calculator. This tool uses data provided by other parties
(such as PV module specs) and makes calculations based on assumptions which may or may not
prove to be valid.
www.midnitesolar
 
Supposedly this system as designed the Kidd is operating at half capacity and has room to double the panels and batteries. What I can not find anywhere is what is the start up draw and running watt draw of my well pump. I really would like to know this one for sure.
 
I am in the process of setting up my basic solar system and I am in the market for a 48V DC to 120/240V inverter charger for under $1000. I need to be able to run my water well (240v) in the event of loss of power. At first it will be a non grid tied system but eventually may want to grid tie as we build it up and add more batteries and panels. To begin with, this system will use four 300 watt panels and eight 6volt batteries. I already have the panels, a Midnight Kidd charge controller and about 100 ft of AWG2 copper wire. From what I have gathered this system as it is will be operating at about half it's capability so we plan to add 8 more batteries and 4 more panels in the near future.

Can anyone recommend an inverter/charger for under $1000 ? Maybe one that could switch automatically to grid if need be down the road?
I have mentioned before about inverter/chargers and there is a supplier just north of Eugene, Oregon that we have done business with a couple of times and that is Don Rowe, www.donrowe.com , it is my personal opinion that you get what you pay for and there is some cheap inverters out there. I prefer having pure sine wave inverters as they operate electronic systems and some motors more efficiently. One thing you have to take into consideration is in running well pumps that they need nearly twice the starting amps than the running amps. Most all inverters have a momentary higher amperage and you need to know that figure or the well pump is likely to overload the inverter, in example, let's just say a 2,000 watt inverter will run a well pump, but if it doesn't provide 4,000 watts for a few seconds the startup of that pump may fail. Give Don Rowe a call, they can probably help figure out what you need, in all our dealings with them they have never tried to sell us something we didn't need or want
 
Thanks @viking. From what I'm seeing a 3/4 hp 230 volt deep well pump will need around 3000 to 4000 watts for startup so I'm looking at around a 6000 watt inverter. Think I'm gonna have to push that under $1000 limit up. I looked at their site and they have some good prices. I'll call them tomorrow to see what they can do for me.
 
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For the benefit of @Bacpacker and anyone else who is building from scratch here is my solar plan for this system. This was designed for the 12 volt trolling motor batteries that I have in my offgrid cabin now. It will be a bit different with the 6volt golf cart batteries that I'm going to use here at the house for this application.

Here's a thought that works with 1 Kid charge controller

4 of the 300 watt panels; 2 series strings of 2 panels each and those series strings connected in parallel

48 volt battery bank

That has the Kid working at half capacity (amps) more or less. Better than working close to the maximum, as far as theory goes. It also cuts the parallel batteries down to only 2 deep; much better than as is now.

If those batteries are about 115 amp hours each then you would have 115 x 2 = 230 AH @ 48 volts = 11040 watt hours. At 50% max discharge = about 5 Kw usable power.

230 AH would be served well with a 20-25 amp charge input. The 4 panels on the Kid would supply 21 amps at 57.6 volts (equiv to 14.4 on a 12 volt battery). Just about ideal for charging.


Now find a 48 VDC inverter.
 
Eight 6 volt batteries in series, or six 8 volt batteries in series will give you 48 volts. If you connect two of your solar panels in series and run an MPPT type solar controller it will give you the 48 volts to charge your battery bank. A person can run up over 100 volts of solar array output into MPPT controllers and set the output charge voltage for the storage batteries to whatever they are 12, 24, 36, or 48 volts, at least that is what my Morningstar solar controller can do, if your controller is an MPPT type, it probably can do the same. My system runs off of 24 volts, my inverter/charger puts out 120/240 VAC, this system is what's called Split Phase and it's like the regular grid power that comes into your home , it's run rate is 4,000 watts with a 5 sec0nd surge rate of 5,800 watts or a 5 minute rate of surge at 4,800 watts, this is in a range that can start a well pump. Magnum Energy which makes our 4,000 watt inverter/charger also makes a 4,400 watt pure sine wave inverter/charger that is rated at 8,500 watts for 5 seconds, they are presently sale priced at $1,699 at Don Rowe, these inverter/chargers are stackable to 4 units, for reference that unit is a MS4448PAE, it runs on 48 volts, our 4,000 watt unit is MS4024PAE which is also stackable to 4 units, both have to be controlled by an ME-RTR in order to be able to stack the units, I bought an ME-RTR just in case I wanted to stack more inverters for higher wattages but as it has worked out the 4,000 watt unit we have takes care of everything I have designed our back up solar system to do. It is best that in designing a solar system to think minimally, if you do it this way, you can keep the costs lower and still have a good system.
 
JAC, now that you have laid out the basics and I looked up Kid solar controllers, I see that they are the MPPT type, very good, sounds like you're on the right track. By the way those Magnum Energy inverter/chargers are heavy transformer based as was the first inverter/charger we bought for our motorhome, that was a 2,000 watt inverter/charger pure sine wave, made by Xantrex, it's amazing what it would do just running off of four 6 volt golf cart batteries, series/parallel for 12 volts and 410 amp-hours.
 
grrrr. Now I'm wondering if since I'm switching to 6 volt batteries with a 165 amp hour rating and the original system was designed for 12 volt batteries and a 115 amp hour rating if I'm better off to go to a 24 volt system instead of the 48 volt system.

This stuff gets real confusing quick like.
 
grrrr. Now I'm wondering if since I'm switching to 6 volt batteries with a 165 amp hour rating and the original system was designed for 12 volt batteries and a 115 amp hour rating if I'm better off to go to a 24 volt system instead of the 48 volt system.

This stuff gets real confusing quick like.
Personally, I'm going with a 48V system. Double the voltage and cut the amps in half. This means you can have smaller wire or less line loss and less heat.
 
When I crunch the numbers I seem to be losing a lot of watt hours by going into these 8 volt or 6 volt batteries instead of 12 volt batteries. That has to be wrong doesnt it?
115 x 2 = 230 AH @ 48 volts = 11040 watt hours
165 x 2 = 330 AH @ 24 volts = 7920 watt hours
 
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You have 165AH at 12V X2=330AH at 12V = 165AH at 24V. You can double the voltage or double the amperage with 2 batteries otherwise you are quadrupling the power by doubling the batteries.

I have wired houses and I have wired boats. AC is a lot easier to figure out. For instance AC you figure out the load and the distance to size the wire. For DC you have to figure the run and the return to size the wire.
 
115 x 2 = 230 AH @ 48 volts = 11040 watt hours
165 x 2 = 330 AH @ 24 volts = 7920 watt hours

That top figure was for eight 12 volt batteries at 115 AH each in two strings of series wired to make 48 volts and 230 AH. This was an old plan I had for 12 volt batteries that I own.

The bottom one is for six 8 volt batteries at 165 AH each in two strings of series wired to make 24 volts and 330 AH



So with the six 8 volt batteries I want to buy I can either run the two strings of 3 batteries each for a 24 volt system or my other alternative is to run six 8 volt batteries parallel for 48 volts and 165 AH

Am I correct?
I've heard it isn't as good to run 6 batteries parallel
 
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Got ya!
 
Been looking at batteries at Sams.

8 volt batteries for 106.30 ea at 165AH and i'd need six of those for a total of 990 AH at $637.80 or
6 volt batteries for 124.88 ea at 230 AH and I'd need eight of those for a total of 1840 AH at $990.04

Think I'm gonna have to go with the 6 volts. Around double the AH for about $300 more.

Waiting for Interstate batteries to call me back with their prices. They have some 6 volt 250 AH batteries.



So far it looks like this is going to be the solar plan:

Two sets of series wired 300 watt panels connected in parallel.
Run through a Midnight Kidd charge controller.
Then into eight 6volt 230AH batteries wired in two banks of four batteries wired in series then those two banks are wired together in parallel for a 24 volt system.
Then into a 24 volt inverter charger that outputs both 120 and 240 volts.
Then that goes into a breaker panel and outputs to the well and maybe a few other loads down the road.
I should have room in this system to double the amount of panels and double the battery bank later on. I will need a switch to connect the inverter to the well because I want the well to stay on the grid until I need it in the event of a power failure.

Because I already have the panels and the Kidd controller it is looking like about $2500 to get this system running. That is not counting wiring, breaker panels, outlets, fuses and lots of other odds and ends. As I mentioned I already have at least 100 feet of 2AWG copper wire I bought awhile back and have been sitting on for this system to use. The run from the panels to the charge controller and batteries is only about 15 to 20 feet.

Once I figure out what exact batteries and inverter I will update this plan.

Anyone familiar with these systems see any issues?
 
Personally, I'm going with a 48V system. Double the voltage and cut the amps in half. This means you can have smaller wire or less line loss and less heat.
How many batteries are you going to run and in what array? I've heard that it is not good to run 6 or 8 batteries in parallel because it makes charging uneven or something along those lines and cuts into the life span of your batteries.
 
The company I bought these from used to manufacture batteries in Alaska. Their recommendation is to run two strings of 48V and then parallel them to the charger/inverter.
 
I just found out that Interstate batteries is now carrying Trojan golf cart batteries and my local dealer said he can get me T105 with a 225 AH rating for $116 each. That is a really good price as I'm seeing them anywhere from $149 to $199 each elsewhere.
 
@viking Would this Inverter work? Looks right to me. Also looks priced low for what it is.
https://theinverterstore.com/product/6000-watt-pure-sine-inverter-charger/
Looks pretty good, tried to find info on if it's transformer based but couldn't find specs, at a rating of 6,000 watts it should weigh over 60 pounds or more as my 4,000 watt unit weighs 55 pounds, as you get into larger inverter/chargers they will weigh much more due to having large cooling fines and much heavier electronics. If this unit has a transformer, it is certainly priced economically. If you can find the spec info I'd like to see that as it would give me a better idea of how it's made.
 
@viking here is the manual and the specs posted at AIMS:

Manual: http://www.aimscorp.net/documents/PICOGLF10w-60w 071618.pdf

Specs:

Specifications
Inverter Output Specifications:

  • Continuous Output Power: 6000 Watts
  • Surge Rating: 18000 Watts (20 Seconds)
  • Output Waveform: Pure Sine/Same as input (Bypass Mode)
  • Nominal Efficiency: >88% (Peak)
  • Line Mode Efficiency: >95%
  • Output Frequency: 50Hz +/- 0.3Hz / 60Hz +/- 0.3Hz
  • Typical Transfer Time: 10ms (Max)
  • THD: < 10% DC
  • Ambient operating temperature: 14°F to 122°F (-10°C to 50°C)

Input Specifications



  • Nominal Input Voltage: 24.0Vdc
  • Low Battery Alarm: 21.0Vdc-22.0Vdc
  • Low battery Trip: 20.0Vdc-21.0Vdc
  • High Voltage Alarm: 32.0Vdc
  • Low battery Voltage Restart: 31.0Vdc
  • Idle Consumption: 76.8 Watts
  • Idle Consumption in Power Saver Mode: 29 Watts

Charger Specifications

  • Output voltage: Depends on battery Type
  • Charger Rate: 85A

Dimensions





  • Unit Weight: 79 lbs.
  • Unit Size L x W x H: 23.5 x 8.5 x 7.0 inches
  • Shipping Weight: 84 lbs.
  • Shipping L x W x H 30.5 x 14.5 x 13.75 inches
https://www.aimscorp.net/6000-Watt-Pure-Sine-Inverter-Charger-24-Volt.html
 

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