Living on mostly 12v and reducing power

Can you provide a photo of the transformer model tag?  I seriously doubt it is an ASL9; for a 15KW PJ

I bought  on ebay  auction  and is probably rebuilt  and is shipped  in 5 days  from walnut  california   warehouse  by UPS  with no damage .  

Well, surprise then...it is an ASL9 core.  Funny that it can't sustain an 7.2kw load...they normally use it in their "20kw" inverter...

.it is an ASL9 core.  Funny that it can't sustain an 7.2kw load...they normally use it in their "20kw" inverter.

I  am sure it can  sustain  8000kw load at  75 degree F .       Nobody  in this  forum  know  what  118 degree F  in the patio  do to the transformer temperature  after one hour  running  a heat pump starting  surge 28000 watts  with the battery voltage  going down  every  5 minutes  and the sine wave  going to a square wave .   Even  RV  have AC  inside to cool the  inverter .     It will be a test I will do with your GS  12kw inverter next summer  and  I do not know if you  will  warranty  a inverter at that outside temperature  before I try .   Thank you  and  nice talking to you .   

My use case is for 2 or 3 times a year, short spells, crank up the quiet 12v generator when the outage extends past a 15 minutes.

if I use lead acid starting battery 48v system, float it, never discharge below 50%, I’ll likely replace  batteries every 2-3 years, for virtually no use, due to self discharge.

I may be able to use AGM 48v system, never discharge below 50%, replace every 5-6 years, due to self discharge.

Move to LiFePo4 or Li-Ion, maybe eek out a longer life expectancy out of the batteries, if they are never charge past 90%, never discharge past 20%, I will likely change batteries every 5-6 years, due to self discharge. I will never be able to charge Li-Ion to 4.2v, since leaving it there & not using it destroys the battery.

Since I use high quality 56v tools on the weekends, I will likely need to replace batteries every 5-6 years. A smart BMS in a tool discharges the battery after 30 days of non-use, extending the life of the tool battery. Tool BMS’s typically don’t limit output, allowing for 4-5C output, to handle spikes.

In the end, I hate replacing my 12v batteries all the time, typically after a few outages. I don’t want to spend a lot more money for just convenience for what I have today for the privilege of re-buying more expensive batteries. I would rather invest in a system where my investment is 1 time on the inverter hardware and multiple times on tool batteries (that I actually use & run down the street to replace) with my 12v quiet generator.

So why not just use the generator instead of the batteries? If the use is for short periods, why bother with batteries at all?

On 8/21/2021 at 7:52 AM, InPhase said:

So why not just use the generator instead of the batteries? If the use is for short periods, why bother with batteries at all?

My 12v generator will run for days with an AGM for peaks, without filling up the tank, it is great! One 1.5K leg of my 12v Bluetooth 3K inverter powers 1/2 the house runs with my heating & ventilation with 2 refrigerators. The other half of the house requires less than 1500 watts, but my Bluetooth inverter is not split phase, therefore the other half remains dark. The A/C load requires 130LRA or 31.2K peak watts, since it cools the space for 2 families, and this is not accommodated.

The GS 12k unit would handle the peak load, while day to day temporary operation would be severely overkill.

Honestly, I was getting ready to modify 2x APC 1500 units to run as master/slave, but it would not give me my A/C and it is a dual bank 24v solution. In the end, I would have to boost 12v to keep those banks supplied with no A/C.

When I saw the Genetry systems, it does the split phase and the 12K gets me closer to getting my A/C working. If I could run it at 12v, it would be perfect!

if I have to buy another generator, I would have to keep it 6 feet from the house, it would be a lot more noisy (the big issue), I would have to keep the fuel constantly topped off. Overall, I don’t want the bother.

I could get a whole house natural gas generator, but it is still noisy & needs to be 6feet from the house. (My 12v generator is so quiet, you can’t hear it run.)

I have been looking at other solutions, including running a motor at 12v from my generator to generate 240 split phase, and just deal with the loss of efficiency. I could do this, enclosed in a garage, or behind a locked walled area. This would still be preferable.

I could also get a wrecked hybrid, and mess with the inverter. I could also get  soft start circuit & talk to my HVAC man to install it, and maybe go with a GS 6K, especially if they would support 12v for me.

Maybe they would have putty on my soul, I don’t know, and ship what my use case needs, instead of me having to hack all kinds of crap together.

7 hours ago, DavidH said:

If I could run it at 12v, it would be perfect!

Ugh, LOTS of amps.

Am working with a commercial customer that is trying to make 12kw 12v inverter--maybe you'll be able to buy an inverter off of them!  However, that's crazy amps--you're talking past 1,500A @ 12v.  Best case inverter efficiency is going to be under 70% simply due to the molecular electrical losses.

That 31.2kw surge?  Let's add 40% simply due to molecular electrical losses, and that's 31.2 * 1.4 = 43.6kw / 12v = a cool 3,640 amps.  This jumps the gap between "stupendously difficult" and "electrically impossible."  Why?  At 12v, if the ENTIRE inverter resistance--battery cables, chassis wiring, MOSFETs, transformer, etc. is MORE THAN 0.0032 ohms (3.2 milliohms), it will be impossible to get 3,640A to flow @ 12v.  Notice that I didn't say that any work was being done with this 3,640A.  The inverter resistance will have to be far less than 3.2 milliohms in order to get any power to flow on the output side...otherwise the entire 40kw gets burned up in wire losses in the inverter, and no significant power is produced.

Let's not mention that the FETs used in the 6k and 12kw GS inverters are rated at 3.5 milliohms on resistance.  And they're very good FETs.

At 48v, add only 20% for losses (probably way overcompensating), and that's only 780A.  Far more manageable!

7 hours ago, DavidH said:

and maybe go with a GS 6K, especially if they would support 12v for me.

Technically CAN support 12v on a 6kw from a hardware standpoint.  But we definitely cannot recommend it--at least not with the current design.  Full 6kw is 600A! 

Have heard that we have 1 GS customer with an inverter wired for 12v, and he's had it up to 5kw with no issues.

it will be impossible to get 3,640A to flow @ 12v.  Notice that I didn't say that any work was being done with this 3,640A.  The inverter resistance will have to be far less than 3.2 milliohms in order to get any power to flow on the output side...otherwise the entire 40kw gets burned up in wire losses in the inverter, and no significant power is produced.

Too  dangerous for fire  and  cost of  wires will probably  be  more than  a  12kw  GS inverter .  I  see on youtube one  FET  is  900 dollars and need  many FETs for an inverter that  one person try  and fail  and gave up after losing  thousands of dollars .    I  am running  60v on a PJ inverter just to  run a heat pump  129 LRA  for little over an hour  no  matter  how  many time I try to run longer  but never longer than  90 minutes .   The transformer just  overheat  and shut down .   

On 10/3/2021 at 8:28 AM, Sid Genetry Solar said:

Ugh, LOTS of amps.

…trying to make 12kw 12v inverter--maybe you'll be able to buy an inverter off of them!  …

That 31.2kw surge?  Let's add 40% simply due to molecular electrical losses, and that's 31.2 * 1.4 = 43.6kw / 12v = a cool 3,640 amps.  …

At 48v, add only 20% for losses (probably way overcompensating), and that's only 780A.  Far more manageable!

I was hoping to over-provision with a GS 12K with 12v in order to keep everything “stock” in my setup.

I figured @ 12v, I could use 4x super capacitor banks in parallel, to provide transient peak current requirements. (48v is much harder to provide the same current surge capacity with Super Capacitors... I could provide vastly more peak current with 4x super capacity banks in parallel @12v rather than 4x super capacitor banks in series @ 48v.)

Well, it sounds like I am going to have to start hacking things up, then.

I will start to work on a “soft start” for my HVAC Compressor, this will reduce my largest load @130 LRA to 130/5.5= 23.6 Amps (This would bring me well within range of GS 6K.)

That leaves me with some questions…

1. Is a GS 6K @ 36v, in ATS mode supportable, if I keep my peak load below 50A @240v

2. Could a GS 6K @ 36v, take solar input from panels & keep my battery bank charged, if my mains are powered (on ATS mode)? (Trying to find an alternative to my quiet 12v generator.)

3. Could a GS 6K @ 36v, take solar input from panels & keep my battery bank charged, if my mains are off (power outage, on ATS mode)? (Trying to find an alternative to my quiet 12v generator.)

4. Is 2 or 3 viable with grid tie inverters, on the output lines of a GS 6K @ 36v?

5. Will an auto-transformer be needed in a supportable solution, for simultaneous 120v split phase & 240v on a GS 6K, to tie the neutral of a split-phase? (I am still trying to be sure on this point... some other vendor solutions require this.)

(I am trying to find the least amount of hacking, at this point, for my whole-house UPS objective… yes, I have read the GS 6K document 2x, it was very good, but before making a big spend, I am trying to get my proverbial ducks in a row.)

3 hours ago, DavidH said:

I was hoping to over-provision with a GS 12K with 12v in order to keep everything “stock” in my setup.

I figured @ 12v, I could use 4x super capacitor banks in parallel, to provide transient peak current requirements. (48v is much harder to provide the same current surge capacity with Super Capacitors... I could provide vastly more peak current with 4x super capacity banks in parallel @12v rather than 4x super capacitor banks in series @ 48v.)

Surge current isn't the consideration at hand.  See, if you had a 12-24kwh battery bank @ 12v, you'd have considerable amperage available.  The issue becomes getting the amperage through the entire inverter and actually being able to accomplish the intended goal without losing the entire power usage in system losses.

Remember, amperage is the enemy of efficiency.  That's why long-distance power transfer is inevitably at as high of a voltage as feasibly and safely possible.  The lower the amperage, the lower the losses.  Simple Ohm's Law.

3 hours ago, DavidH said:

I will start to work on a “soft start” for my HVAC Compressor, this will reduce my largest load @130 LRA to 130/5.5= 23.6 Amps (This would bring me well within range of GS 6K.)

95% load anyway.  6000W / 240v = 25A.  Remember that the LRA rating is <1sec, so it won't have any bearing on system capacity (i.e. heat limits), but rather entirely an absolute power limit.  No matter what kind of "soft start" you come up with, you will not be able to reduce the startup surge to the FLA rating...that's just how synchronous AC motors work.

3 hours ago, DavidH said:

1. Is a GS 6K @ 36v, in ATS mode supportable, if I keep my peak load below 50A @240v

Well, 240v * 50A = 12,000W, so not exactly. 

ATS function isn't dependent on battery voltage though; if it works at 48v, it'll work when configured at 12, 24, or 36v as well.

3 hours ago, DavidH said:

2. Could a GS 6K @ 36v, take solar input from panels & keep my battery bank charged, if my mains are powered (on ATS mode)? (Trying to find an alternative to my quiet 12v generator.)

3. Could a GS 6K @ 36v, take solar input from panels & keep my battery bank charged, if my mains are off (power outage, on ATS mode)? (Trying to find an alternative to my quiet 12v generator.)

GS inverters as of yet do not have a solar charge controller built in.  However, they can charge from AC input--though the AC input will have to be able to power the entire load in addition to the battery charge power requirements, in order to charge the batteries.

3 hours ago, DavidH said:

4. Is 2 or 3 viable with grid tie inverters, on the output lines of a GS 6K @ 36v?

Yes.  It'll help considerably to have a Rev. C control board in the GS inverter (which I FINALLY just ordered last night).  Once we receive them, all GS inverters will ship with a Rev. C control board.

Bonus points if your grid-tie inverters support frequency shift throttling (most cheaper/readily available grid-ties don't)...if so, the GS inverter will be able to gently regulate the grid-tie output as needed for battery charging + loads, etc.

If the grid-ties do not support frequency shift throttling (i.e. on/off), the system will be far cruder...but should still work quite well.  (If there's a power excess, the inverter will start shifting the output frequency from 60Hz up past 62Hz--or at least until the grid-ties trip off.  Expect a slow oscillation here, as most grid-ties will then run a 5-10 minute timeout before they try to power back up again.  If the power needs / battery charge is still less than the grid tie inverters' total output power, the GS inverter will trip the grid-ties off again.)

Curious then if you have grid-tie inverters already picked out...if so, what are they?

3 hours ago, DavidH said:

5. Will an auto-transformer be needed in a supportable solution, for simultaneous 120v split phase & 240v on a GS 6K, to tie the neutral of a split-phase? (I am still trying to be sure on this point... some other vendor solutions require this.)

No.  GS inverters provide true split-phase output, no hacked-up solutions needed.

Will an auto-transformer be needed in a supportable solution, for simultaneous 120v split phase & 240v on a GS 6K, to tie the neutral of a split-phase? (I am still trying to be sure on this point... some other vendor solutions require this

Do not use an  autotransformer  because it max out at 5000 watts  .   See youtube  review on Gowatt using   autotransformer to make 240vac and  surge exceed  5000 watt  and  the  neutral will be disconnected  and  the ground wire  will become  the neutral wire and a person can be electrocuted or the house catch on fire .    Gowatt  is HF inverter  and not true split-phase .    

On 10/7/2021 at 5:39 PM, Sid Genetry Solar said:

95% load anyway.  6000W / 240v = 25A.  Remember that the LRA rating is <1sec, so it won't have any bearing on system capacity (i.e. heat limits), but rather entirely an absolute power limit.  No matter what kind of "soft start" you come up with, you will not be able to reduce the startup surge to the FLA rating...that's just how synchronous AC motors work.

Well, 240v * 50A = 12,000W, so not exactly. 

It seemed Micro Air Soft Start Kit

• Reduces peak from 70Ah to 30Ah
• Reduces avg from 12Ah to 9Ah

https://youtu.be/uowVMYuPs-U

I saw it on YouTube, must be true! Lol! 🙂

On 10/7/2021 at 5:39 PM, Sid Genetry Solar said:

GS inverters as of yet do not have a solar charge controller built in.  However, they can charge from AC input--though the AC input will have to be able to power the entire load in addition to the battery charge power requirements, in order to charge the batteries.

Would optimizers on the panels provide a constant voltage, then I could plug the DC lines into the battery input, use diodes to keep the battery isolated, use a separate battery charging circuit?

On 10/7/2021 at 5:39 PM, Sid Genetry Solar said:

Curious then if you have grid-tie inverters already picked out...if so, what are they?

I have a temporary source for used 61v panels used USA built panels. I was designing a retractable black pipe racking system.

I had my heart set on 2x $440 discontinued Delta H6 hybrid inverters, that would only run in grid tied mode (due to crippled software), and was considering used SPIM08HP batteries for ~600v DC battery assembly (your earlier messages about higher voltage impacted me 🙂 ) (The delta looked like it would shut off with frequency shift, while it had no real intelligence besides grid tie & charge batteries & dump power from batteries when sunlight was too low. (It looked like the input panel could set the range for frequency shift shutoff, so I was ready to ask you if the GS could gradually shift to disable multiple grid tied inverters progressively, one at a time 🙂 ) 

The Delta sold out a few days back, shortly before I was able to finish the design & pull the trigger on everything.

No more Delta grid tie blew up my design.

Back to ground zero.

Every time I turn around, I am unhappy with what I see.

I may considering returning to a wall of EGO batteries for a GS to run as a UPS. (I still need to design a large 56v interconnect with isolations.)

I am considering building my own solar panel optimizers, to dial each solar panel DC output voltage to what I choose (61v DC solar panels leave me with too few inexpensive options, but close enough to an EGO battery wall.)

I contemplated DIY grid tie circuits, at whatever voltage I dial in. 😞  

I thought about 120v or 240v DC solar input, convert to a square wave, trim to a stepped sine wave… then I concluded I did not want to be GS since I had already watched all your videos! 🙂 

I am considering building my own solar panel optimizers, to dial each solar panel DC output voltage to what I choose (61v DC solar panels leave me with too few inexpensive options, but close enough to an EGO battery wall.)

Are your 61v DC solar panels  made by Sunpower ?     All my  solar panel are  61v Sunpower which  leave little option  but  MSB   60amp  119 dollars  will  work  to run my powerjack with 16s battery .   

  On 6/29/2021 at 9:11 PM, DavidH said:

My question was just before the gs12 test. I was hoping for a good result on the gs12.

I'm not quitting on the 12kw.  Have 3 things to try...should be able to get it working one way or another!  For one, FET crosstalk/drive issues are the bulk of it...need to figure out how to get the best drive signals on the gate without punching the gates out with overvoltage...AND limit the maximum throttle.  I recall that @Ben managed to explosively blow out a set of FETs with no load on the inverter...by connecting the AC output wires up wrong.  That tells me that these high-wattage transformers won't accept a square wave input...they'll basically dead-short the battery and blow the FETs out.  So I need to determine what a safe maximum throttle is...and go 20% less than that.

I  replace  the 15kw powerjack  long mainboard  with the short mini mainboard like in the 20kw powerjack .   The  long  trace inside the long mainboard  shorted by crosstalk  at high surge will blow up all the FETs and LF driver .  I  fix the short and use the damage mainboard  for 6  more  capacitors  connected to the  4 on the mini mainboard  so total  of 10  100v 10000uf  capacitors  .    Be sure to precharge the  capacitor  before connecting  battery .   The new  AMG powerjack has a  mini mini mainboard  where the trace inside the mainboard  is so short that there is  no crosstalk  .  

Sure can, out of the box.  While I have yet to test this function on an actual grid-tied setup, it IS written.  If the inverter detects reverse power flow on the AC Output sensor (beyond a threshold), it'll start to shift the frequency up over 2-3 seconds up to 62Hz.  If the reverse power is still present at that point, it'll shut down with a GTM Regulate Fail error.  (Grid Tie Master regulation fail--"I tried to turn it down, but it won't turn off!")

The goal of this would be to "throttle down" a smart grid-tie inverter to a point...then if power starts flowing forwards again, the frequency shift will start to come back down.

I'm not familiar with "optimizers", could you provide more details?  (Part number?)

You could use diodes alright, but prepare to heatsink 'em good, as they'll get HOT under full load!  6kw @ 80% and 48v is 150A.