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4000 watt Inverter on 12 V?

Supervstech said:
DC voltage can make a HUGE dangerous mess if metal objects are poorly placed... if you are touching both poles on the battery with sweaty hands, or just being careless around the terminals...

as long as you don’t do those things.
Work on ONE SIDE OF THE BATTERY AT A TIME.
and cover the terminals with non conductive protection, plastic etc. Don’t wear jewelry around the wiring, and never work on more than one side of the battery at a time.
also, never work on more than one side of the battery.
12V, 24V, 36V, and 48V are all very dangerous if not respected.
24V is nearly harmless, but can SERIOUSLY shock you if the right conditions are present.
Don’t let those conditions exist around the battery, and 48V is as safe as 12V... but, disrespect 12V, and it irritates you... disrespect 24V, and you get a shock... disrespect 48V... yeah, bad times.
Click to expand...

I at least know those things, I like what you did there with the working on one side thing. ;-)
 
GXMnow said:
What is going to charge the batteries? Is this solar or just grid charge to have standby for an outage?

There are pros and cons to running the current through the BMS. In my case with the JK active balance "smart" BMS it is nice to be able to monitor the battery state, see the full charge and discharge current, have an accurate count of Amp Hours remaining, etc. When you bypass the BMS with the contact for the main load, you won't have that monitoring, but it will still protect the battery from discharging too low.

That's true, the Kill-O-Watt does not see the startup surge. A 2 year old LG Fridge should easily fit in the 5 x run current range. Many newer fridges have inverter compressors which are far less of a start surge. But 4 years old is a question.

A 12 volt system with four 200 AH cells will only provide 1,000 watts for 2 hours. That might be enough, but it will be close with the fridge, TV, PC's, etc. Going to 8 cells gives you double the power. 2,000 watts for 2 hours, or the same 1,000 watts for 4 hours. . You can run them in 8S series for 24 volt, or 4S2P and stay 12 volt, but with the higher current and thicker wire etc. If you have devices that will run directly off 12 volts, then you do have some reason for staying at 12. If it is all going to be running off of the inverter, then there is no big reason to stay at 12 and just go to 24.
Click to expand...

My plan was to charge via grid for now, then eventually adding a solar charge controller after the fact. I have 5 315 Watt panels in my shipping container I haven't gotten around to installing on racks. I bought a full solar package at the beginning of last year before I knew much, I just sold the 2 245 AH 12 V AGMs that came in the package last Friday (lost a few hundred dollars because of it). I have a some cable, a breaker box, a Samlex 1500 Inveter (not the Evo), and a Midnight KID MPPT Charge Controller. The package was stupidly designed by at guy at Iron Edison and I made a knee jerk decision buying it...

Needless to say I want to figure this out. So it sounds like the Kill-A-Watt may not be what I needed to determine the draw of the refrigerator? The Klein Clamp Meter SmoothJoey suggested above would be better I gather, granted it's over hundred bucks. :) I mean I guess the Kill-A-Watt will help with other basic need analysis.

So I see, 24 V will be less current draw. If I went to 48 V that would be me 4000 watts for 2 hours with 200 Ah?

48 V I was originally trying to hold off on until I start building a full house system, which will be years down the road. I just wanted to build a hand truck system for a couple hours of basic emergency power so I don't have to haul out a generator, extention cords, mess with fuel, have the noise and smell. Also I plan on connecting it to panels as well, panels I already have...

What would you all suggest in general?
 
If power is only out for a few hours, then why would you be concerned about running a refrigerator and freezer? These will be just fine for a few days even if you're not leaving the door open all the time.

My current plan for the future in my house is to put in a solar system where the system gives me a return back everyday for the investment. 48V battery bank, permanently installed inverter, put larger loads like refrigerator and freezer on the circuit plus some comfort items like TV and some lights. The all in ones like the Growatt are the way to go, when battery power cuts out, it automatically switches over to grid power. If grid is down, then a portable genny would come into play as I need to pump water. But the battery bank allows my utility bill to be lower, provide power to various appliances if grid goes down for a short time (I'm talking a few days). Genny is only run every few days to build up water supply if power grid goes out for extended time. My system will not be grid tied but instead load reduction.

As for the small emergency system on a hand truck, basically you are either building a type of DIY solar generator or you could just buy a Bluetti.
 
Devin82m said:
What would you all suggest in general?
Click to expand...
Don't buy system components until you get the lay of the land so to speak.

There are less expensive clamp meters.
Maybe someone else can provide a link for the red one that is popular here(name escapes me).
 
smoothJoey said:
Don't buy system components until you get the lay of the land so to speak.

There are less expensive clamp meters.
Maybe someone else can provide a link for the red one that is popular here(name escapes me).
Click to expand...

Yeah, I'm going to wait until I figure this out. I may even just hold on the refrigerator bit.

Quick question, if I decided to stick with a 12 V system and power small stuff (laptop, router, mode, and possible LCD TV) will my existing Samlex 1500 watt be too much for the 120 watt BMS? I mean especially when the full 1500 watts probably won't be drawn? Or should I stick with 1000 Watts?

Also, as for large systems for the whole house to power everything, are there particular brands of LiFePO4 people buy for that? I mean like full 48 V systems. I was doing research for the future and just saw an EEVBlog video where he upgraded to 8 Kw and is using micro inverters, which I didn't know they had, pretty cool stuff. One of these days I may just finance a full system and have it installed so I don't have to mess with it. The only thing is I want to beable to replace the BMSs, inverters, and charge controller with backups. I'm paranoid about EMP and all that so I keep spares of things.
 
Just reading this thread, so this info is a bit late.

Steve Tecza (the Overkill BMS guy) was exchanging emails with me before I bought my BMS from him. I was concerned about using the 100A 24V BMS for my system, because I was worried about induction motor inrush current. 100A would be more than enough for normal operation, but when my well pump starts I know it is going to be some over that. He informed me that the 100A 24V BMS can handle up to 280A for up to 10 seconds. That was more than enough for me.
 
Ah, good to know.
Horsefly said:
Just reading this thread, so this info is a bit late.

Steve Tecza (the Overkill BMS guy) was exchanging emails with me before I bought my BMS from him. I was concerned about using the 100A 24V BMS for my system, because I was worried about induction motor inrush current. 100A would be more than enough for normal operation, but when my well pump starts I know it is going to be some over that. He informed me that the 100A 24V BMS can handle up to 280A for up to 10 seconds. That was more than enough for me.
Click to expand...

Ah, good to know, thanks for sharing. I just emailed them too to see what they suggest.
 
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By the way, as far as clamp meters with peak amps function, I have two that I've been happy with. The Klein CL800 was what I bought to make sure I had a good brand, and it has been good to me: https://www.amazon.com/gp/product/B019CY4FB4

With the Klein up in the mountains buried in snow, I needed a second one here at home for projects. Harbor Freight had the AMES CM1000A on sale a while back: https://www.harborfreight.com/cm1000a-1000a-t-rms-acdc-clamp-meter-64017.html I think the Ames has a little better inrush current function, but they both are good.
 
Supervstech said:
Lowes has an $89 Klein meter with dc amps and inrush...
Click to expand...

OK, so I have canceled 2 orders with Amazon now because people suggest meters that don't meassure inrush. So I for sure need the inrush capability to meassure the surge of the compressor motor on my refrigerator? I want to confirm before I click another order button. :-D
 
Horsefly said:
Just reading this thread, so this info is a bit late.

Steve Tecza (the Overkill BMS guy) was exchanging emails with me before I bought my BMS from him. I was concerned about using the 100A 24V BMS for my system, because I was worried about induction motor inrush current. 100A would be more than enough for normal operation, but when my well pump starts I know it is going to be some over that. He informed me that the 100A 24V BMS can handle up to 280A for up to 10 seconds. That was more than enough for me.
Click to expand...
That is the difference between continuous and surge ratings.
 
So from what I can tell on the Klein site, only two models have the Inrush feature and none of the models suggested here are those two models. The CL450 and the CL900.
 
Devin82m said:
So from what I can tell on the Klein site, only two models have the Inrush feature and none of the models suggested here are those two models. The CL450 and the CL900.
Click to expand...
I have a Klein cl390 and it is an ac/dc clamp with inrush feature.
I've used it on my microwave and on my air conditioner.
 
Interestin
smoothJoey said:
I have a Klein cl390 and it is an ac/dc clamp with inrush feature.
I've used it on my microwave and on my air conditioner.
Click to expand...
Interesting, on the Klein website you can compare and they had a PDF that compares them and the 390 does not have the inrush option.
 
Devin82m said:
Interestin

Interesting, on the Klein website you can compare and they had a PDF that compares them and the 390 does not have the inrush option.
Click to expand...
David Poz thought the uni-t was pretty good and its inexpensive.
 
Wow it is difficult finding a decent clamp meter that does both AC/DC and has an inrush feature. The only one I can find that you can't find in stock in the Klein CL900 which is $150 or the CL450 which is $175. The Kaiweets brand only has one that fit that criteria and it's not in stock anywhere. Uni-T has a couple, but one is only 100 amps, which is kind of useless in any large battery systems I could build. So complicated.
 
Devin82m said:
I mean instead of buying another 4 cells to make 200 ah now I have to use them to make a 24 v 100 ah battery.
Click to expand...

Stop thinking in amp-hours. You need to think in watt-hours. A 24V 100Ah battery has the same amount of energy as a 12V 200Ah battery or a 48V 50Ah battery. Amp-hours can only be compared directly between batteries at the same nominal voltage. A Watt-hour is essentially the amp-hour with the voltage multiplied, so you can compare capacities across different battery systems.
 
Devin82m said:
OK, that helps, how many amps would work?
Click to expand...
To measure the in-rush of a fridge 50 amps is probably plenty.
For the ac side you the in-rush of your inverter is not practical to measure.
If you were to make the 12 volt system you've been planning on the largest dc clamp I'm aware of 400 amps so that is just barely big enough.
My Klein cl390 does 400 amps, but I've not really used the in-rush measurement on the dc side.
 
smoothJoey said:
To measure the in-rush of a fridge 50 amps is probably plenty.
For the ac side you the in-rush of your inverter is not practical to measure.
If you were to make the 12 volt system you've been planning on the largest dc clamp I'm aware of 400 amps so that is just barely big enough.
My Klein cl390 does 400 amps, but I've not really used the in-rush measurement on the dc side.
Click to expand...

OK, then it sounds like that Kaiweets may be a good option then. I don't see the point of measuring anything on the DC side since I will use the formulas to make sure I am within the margin.
 
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Another question, if I put a 1500 watt inverter on a 12 V system but don't draw the full 1500 watts (probably more like 800 or less) from basic electronics like router, modem, laptops, and monitors, will that be too much? I figured a little under 600 watts in my home office for the stuff I use every day. There are other things in the office, but they aren't used every day or I know they are just too much for at such a small system.

I ask because I already have a Samlex 1500 Watt Inverter, a Midnight Solar KID Solar Charge Controller, and 5 315 Watt panels (not setup yet).
 
Devin82m said:
Another question, if I put a 1500 watt inverter on a 12 V system but don't draw the full 1500 watts (probably more like 800 or less) from basic electronics like router, modem, laptops, and monitors, will that be too much? I figured a little under 600 watts in my home office for the stuff I use every day. There are other things in the office, but they aren't used every day or I know they are just too much for at such a small system.

I ask because I already have a Samlex 1500 Watt Inverter, a Midnight Solar KID Solar Charge Controller, and 5 315 Watt panels (not setup yet).
Click to expand...
That should work fine.
 
Yes you can, I use 12V 3000W inverter in my system even though the load is only around 400W (TV, computer, lights, air cleaner), but I had to use 3000W so my fridge can start up, once it is running , it only draws 200W and it cycle on and off every 20 minutes or so, so my average draw is only 400 ~500W or so.
 
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