Need inverter that meets my systems requirements

Doin it

Doin it

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Mar 17, 2019
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I could use some help finding an offgrid pure sine wave inverter.
Requirements;
Needs to operate at a voltage range up to 64v minimum
The low voltage that the inverter stops producing power needs to be adjustable
Has to supply 120v to loads

found this one (48v 1200w) that meets all of the requirements except it seems as if the voltage parameters for when inverter stops producing power is not adjustable, I thought all victrons parameters where adjustable with the dongle thing but I guess this one isnt smart.. Ive found many other brands like this that parameters arent adjustable but take over 64v and supply 110v...

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Then I found this one (48v 1200w) and parameters are adjustable (or atleast should be adjustable for how much it costs) but for some reason the max volts it can handle was dropped to 62v (need 64v minimum)

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This one (ms4048) will work (I think voltage shutoff is configurable) but it also had an ac charger (which I dont need) and its expensive

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The inverter needs to be able to run a small deep freezer and a small (300w) centrifugal blower fan and a grundfos water pump (roughly 100w)
 
I guess I could use an inverter like in the first pics (supplies 120v and will handle up to 68v) and since the parameters (doesnt have communication port) arent adjustable, I would then install a separate low voltage disconnect on the battery to stop the inverter from producing power at desired low voltage of 58.6v, but then how would I get the battery to reconnect to the inverter when batteries reach full charge (64v)?
Really would be nice to not have to do all that and just have an inverter that could take atleast 64v, supplies 120v, and has adjustable recovery and shutdown parameters so I can set them for my 16s lithium ev battery bank
 
Ik no one has time these days with how busy we are but just know if I had the knowledge to help someone else in need I would. Thx
 
I think with the various time zones that most people who know the information needs to be taken into account. Also, this is a forum, not a phone call. Just because you post something, doesn't mean it should be responded to within a few hours.

And, very seriously, the world is dealing with a health crisis. So, I think it is more important that people focus on their health and those around them than on the forum.

Your post is only 11hrs old at this time, on a monday, with a health storm going around the world. Patience is required in times like these.
 
Agreed,. Ive been not doing jobs for anyone lately due to the health crisis, so I have a lot of time to think about saving energy- getting some offgrid power going just in case it gets a lot worse,, this is kinda why I was trying to get a response quickly, but was not implying that it was taking to long to get a response.. I will patiently hope for help figuring this out soon
 
Why did you set your battery to 64v?? Prebuilt batteries?

Therese an reason why k state 14s is the most optimal when using 3.7v lithium cells. To me it looks you choosen a battery size that removed 95% of all inverters out there
 
Daromer,, yes they are prebuilt. I did end up excluding a lot of off grid inverters due to the battery voltage I chose. Reason; my grid tie inverters operating voltage is 45-90v. I chose a battery voltage that is in the middle of that so I didnt need as many amps coming from my array which (Im sure u know) lowers amperage heat lose and smaller wire sizes needed. Also the grid tie inverters I have work better and are more efficient using 64v (16s ev pack). When I chose this voltage I made sure there was offgrid inverters that could operate at this voltage, but I didnt check to make sure the offgrid inverters low voltage shutoff was adjustable.
It think the bigger issue is that the inverter has to have adjustable low voltage shutoff, I havnt found many with that option. I have found many that will be able to use 64v. Some cut off at 62v but most (of the 48v inverters) Ive seen can use 64v or more.. Alot off grid inverter manufacturers have a 48v option (usually also will operate at 64v) and will also produce 120v. So Im looking for manufacturers-offgrid inverters that have adjustable parameters
 
Doinit said:
It think the bigger issue is that the inverter has to have adjustable low voltage shutoff, I havnt found many with that option. I have found many that will be able to use 64v. Some cut off at 62v but most (of the 48v inverters) Ive seen are 64v or more.. Alot off grid inverter manufacturers have a 48v option (usually also will operate at 64v) and will also produce 120v. So Im looking for manufacturers-offgrid inverters that have adjustable parameters
Click to expand...
Controlling inverter on/off by battery voltage was always a key thing for me from the git-go. I originally bought/used Samlex battery-guard(s) that let you choose from about 10 different ranges and they had one that was 24v/200a. However, when I went to 48v system... I also went to Midnite Classic controllers... which happen to have auxiliary on/off and relay (your choice) based various things - one of which is battery voltage. So now, I use this to turn on/off my inverters - and can do it thru the computer and custom software. Another variation on this would be Batrium - the expansion board could be used for this as well. There are other solutions as well.

Ultimately, I like having a separate, customize-able, controllableon/off control based on battery voltage rather than try to tie it in with the inverter itself.
 
Offgridinthecity, Im fairly certain it said in the manual that the outback charge controller I have has an aux that can be used for lvd. I think it would simplify the setup if the inverter has the adjustable low voltage shutoff capability.. my cheap gridtie inverters even have that capability... I guess if I cant find an offgrid inverter reasonably priced that has the adjustment capabilities (low voltage shutoff) I need then Ill use the outbacks aux and a relay.. I kinda checked into that,,, havnt yet been able to find a relay that can handle 64v 45amps.

Just found this, will it work for the relay that the outback triggers and handle battery voltage (64v) and amps 45

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Or this one?
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Doesnt say dc tho, does that matter?
 
I tried SSR twice with no luck (they would switch on but not off) and finally settled on "Baomain JQX-62F-2C Coil Voltage DC 12V 80A DPDT Electronmagnetic Relay" https://www.amazon.com/gp/product/B010L02RUO/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 which I have direct experience will work at 45a level.

However...
1) Look at the last half of this recent threaddiscussing various relays -https://secondlifestorage.com/showthread.php?tid=8794&highlight=relay
and
2) I outgrew the 45a relay as I'm up in 48v@250amp range now... so I switched over to wiring into the inverter's on/off switch and bypassing the power leads. This is typically a simple circuit close/open - e.g. trivial voltage / amps - and I think almost every inverter will have an on/off switch.

TMI - in AIMS case, they have an RJ45 jack for 'external control' and its really simple - short wires 3-5 for 'Rocker switch position on' or wires 5-7 for 'Rock switch power save on'.
 
OffGridInTheCity said:
I tried SSR twice with no luck (they would switch on but not off) and finally settled on "Baomain JQX-62F-2C Coil Voltage DC 12V 80A DPDT Electronmagnetic Relay" https://www.amazon.com/gp/product/B010L02RUO/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 which I have direct experience will work at 45a level.

However...
1) Look at the last half of this recent threaddiscussing various relays -https://secondlifestorage.com/showthread.php?tid=8794&highlight=relay
and
2) I outgrew the 45a relay as I'm up in 48v@250amp range now... so I switched over to wiring into the inverter's on/off switch and bypassing the power leads. This is typically a simple circuit close/open - e.g. trivial voltage / amps - and I think almost every inverter will have an on/off switch.

TMI - in AIMS case, they have an RJ45 jack for 'external control' and its really simple - short wires 3-5 for 'Rocker switch position on' or wires 5-7 for 'Rock switch power save on'.
Click to expand...
Why would the ssr not switch off when the battery reaches disconnect voltage, and switch on-reconnect when battery reaches reconnect voltage?

After reading that recent thread I am now more confused.. trying to figure out if a relay is for ac or dc so I dont fry the contacts... I was under the impression that if I wanted to use an ssr for dc then I should derate the volts, like if it said 600vac then it would only handle like 150vdc, apparently I was wrong.

Offgrid are u saying I can use a relay on a wire from the inverters on/off switch so a high current-voltage from battery doesnt need to be switched? if so could that not do damage to inverter switching off its power when its under high load? If it will not cause damage then how do I wire up the simple circuit closed/open as u described it?

Also u were saying about shorting 5 and 7 etc on an aims inverter thru the RJ45 jack.. hows this done?, and is that safe to do under load?

Will the contactor u shared from amazon safely handle 64v 45amps?
 
>Why would the ssr not switch off when the battery reaches disconnect voltage, and switch on-reconnect when battery reaches reconnect voltage?
Don't know why they fail... maybe because it was DC rather than AC or it was 'fake' - they just didn't work for me. I tried 2 different ones :)


>After reading that recent thread I am now more confused.. trying to figure out if a relay is for ac or dc so I dont fry the contacts...
[size=small]>Will the contactor from Amazon u shared from amazon safely handle 64v 45amps?[/size]
Yes - its confusing. That's why I offered an example of one (above rated for 80a contactors) that worked for me over hundreds of on/off at the 45a level.
I also found a 48vc coil and400a DC contactorGIGIVAC relay (GV200FA-1)-https://www.gigavac.com/sites/default/files/catalog/spec_sheet/gv200.pdf
Here's a 150a version on ebay -https://www.ebay.com/itm/Gigavac-MX...AOSw0HVWDApN:sc:FedExHomeDelivery!97504!US!-1

>Offgrid are u saying I can use a relay on a wire from the inverters on/off switch so a high current-voltage from battery doesnt need to be switched?
Absolutely. Here's a pic of a common/very-cheap Reliable to illustrate. Notice the rocker switch (on/off) in the picture? You simply take the cover off and run a pair of wires to the studs of the switch so when the relay makes contact its the same as closing the switch.
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>Also u were saying about shorting 5 and 7 etc on an aims inverter thru the RJ45 jack.. hows this done?,
I do 3 and 5 as this is full power mode. 5 and 7 is power saver mode which doesn't work for me. 3-5 are 1 position of the rocker switch and 5-7 are the other position. It really is 'just a simple switch' wiring wise - nothing special.
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>and is that safe to do under load?
When an inverter is off therecan't be a load because the inverter is not producing any power. When its on and you turn it off - each particular inverter will likely behave a bit differently but in AIMS case the power 'rapidly' drains away. You'll have to experiment for your situation.

In my specific case - theinverter output is connected to the generator side ofautomatic transfer switches (ATS). So when the inverter comes on - the ATS will delay the generator power (once it senses it) switch-over by about 20secs - giving plenty of time for the inverter to fire up 100%. Once the inverter goes off - the ATS senses loss of power and switches back to grid automatically. Here's an example of a good 30a @120v ATS... https://www.amazon.com/Go-Power-TS-...3?keywords=go-power+ats&qid=1584548221&sr=8-3
 
Very useful info for a rookie like myself.. thx a lot ken!

If I end up getting an inverter that is not aims, which relay would u recommend for switching the rocker switch on/off ?

Could u plz draw me up a simple (not simple for me) wiring diagram that includes the rocker switch, relay and 12v coming from charge controller.


Im thinking about getting an aims, but 64v is max for the inverter. My battery gets to 64v. Would that be a problem?

So for the RJ45 ,,, I would just use 2 of the contacts of the relay for wires 3 and 5 of the RJ45 chord and the other 2 contacts of the relay are the trigger positive and negative coming from the charge controllers auxiliary
 
Doinit said:
Very useful info for a rookie like myself.. thx a lot ken!

If I end up getting an inverter that is not aims, which relay would u recommend for switching the rocker switch on/off ?

Could u plz draw me up a simple (not simple for me) wiring diagram that includes the rocker switch, relay and 12v coming from charge controller.


Im thinking about getting an aims, but 64v is max for the inverter. My battery gets to 64v. Would that be a problem?

So for the RJ45 ,,, I would just use 2 of the contacts of the relay for wires 3 and 5 of the RJ45 chord and the other 2 contacts of the relay are the trigger positive and negative coming from the charge controllers auxiliary
Click to expand...
IF you had a Midnite Classic Controller, you could use the Aux1 on/off switch directly to turn the inverter on/off. The yellow is the midnite software interface where I've set inverter off at 49.5v and inverter on at 53v.

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The Midnite Classic has an option for Aux1 to send 12v when on and 0v when off (instead of just being a switch). So here's the same thing as above except we're using a relay with a 12v coil. This arrangement (using a relay) would let you do + and - power leads to the inverter as long as the contact can support the level of amps.

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>Im thinking about getting an aims, but 64v is max for the inverter. My battery gets to 64v. Would that be a problem?
The AIMS docs say 64v will trigger a high voltage alarm... so 64v would work but it might be a touch too hi - you could try it. If it was a touch to highwhy don't you simply lower thebattery charge max to63v? I'm sure your charge controller let's you configure the the absorb/float values... so just configure them to be slighly below 64v.

>which relay would u recommend for switching the rocker switch on/off ?
Any / cheap relay with at least normally open contact as there is no amperage involved - its like a small transistor radio on/off switch - milli-amps at best. You just need to match the coil voltage to whatever is turning the relay on/off. If that were a Midnite Classic - it would be 12vdc.
 
Yes I could lower voltage of battery bank to 63v but I would prefer to keep the battery capacity I have.. its 6kw battery bank and Im only getting 3kw (is this normal?) out of it with gridtie inverters set to shutoff at 58.5 and on at 64v.

Option 2 using a relay, if the inverter doesnt have the RJ45 jack then I would connect to the rocker switch contacts instead?

Above u said that
as long as the contact can support the level of amps
but u also said
Any/cheap relay with at least normally open contact as there is no amperage involved
Do I have to be concerned with amperage in wires that connect to inverters rocker switch contacts if I wasnt using an aims?
 
Doinit said:
Yes I could lower voltage of battery bank to 63v but I would prefer to keep the battery capacity I have.. its 6kw battery bank and Im only getting 3kw (is this normal?) out of it with gridtie inverters set to shutoff at 58.5 and on at 64v.
Click to expand...
Earlier you stated "...using 64v (16s ev pack)...". A 16s lithium-ion would be 16*4.2 = 67.2v ... is this what you have? / need more detail to answer these questions.

[size=small][size=small]Howeiver, as an example,Lithium ionbased64v/16 = 4.00v/cell vs 63.5v/16 = 3.97v/cell - trivial amount of power 'lost' if you pull back from 64v hi to 63.5v hi.
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Doinit said:
Option 2 using a relay, if the inverter doesnt have the RJ45 jack then I would connect to the rocker switch contacts instead?
Click to expand...
Yes.


Doinit said:
Do I have to be concerned with amperage in wires that connect to inverters rocker switch contacts if I wasnt using an aims?
Click to expand...
Not likely - it should be< 1a A small rocker switch does not carry an amperage,
 
I do have a 16s 67.2v lithium pack, but only charge the pack to 64v, isnt it best to not charge them to max? I thought charging to only 4v a cell was recommended. Or maybe thats only recommended for used lithium-ion cells, which is what I have, but was only supposed to only have 18000 miles on the car..
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I could get more out off the batteries.. drain them down to the minimum they recommend 56v (3.5v per cell) which is way below the knee, and charge up to 65.6v (4.1v per cell), would be a lot closer to 3kw per battery then... kinda scared to do that tho.. using the 58.6v to 64v charge parameters the cells have stayed perfectly in balance (less than .1v difference,, Im about to get a bat-go (or something similar) to keep track of the cells and balance a little.. Maybe then Ill expand the charge parameters.. wow I just realized thats 4.2v of battery voltage I could be using,,, i suppose thats where the rest of the capacity is..

If I use an aims as u recommended I could lower the batteries high charge to 63.5v (instead of 64v) and lower the bottom to 58.1v (instead of 58.6v) and still have same capacity Im using now
 
I see - 16s lithium-ion. I hate to see you 'give up' the ability to charge up to 4.1v/cell etc inverter wise. Take a look at Magnum -https://www.solar-electric.com/lib/wind-sun/MS-Series-manual.pdf (seems like a very solid main stream brand). They have 48v @ 4000watts and you can double up to get 48v@8000watts if you want.

See page 51 - it shows
HBCO (Hi Battery Cut Out) of > 67.6v ... 67.6/16 = 4.225, so it would let you use 100% of your battery.
LBCO (Low Battery Cut Out) down to 40v (adjustable).

My personal recommendation would be to go with something like this - that gives you full options.

For example, my design is geared for XX kwh(on average) out of my battery bank - this is needed to balance PV input vs load so I don't loose any PV power. I do this on averagein the range of 3.9v/cell hi and 3.54v/cell low. As my battery degrades, I will need to increase the range to maintain the same XX kwh. I plan to go all the way to 4.15v near the end-of-life of the battery to use it all up! So in your case, I would suggest that (as you originally posted) you find equipment that gives you the full range of options.

The other track - of using relay to control inverter on/off is still valid.
 
OffGridInTheCity said:
I see - 16s lithium-ion. I hate to see you 'give up' the ability to charge up to 4.1v/cell etc inverter wise. Take a look at Magnum -https://www.solar-electric.com/lib/wind-sun/MS-Series-manual.pdf (seems like a very solid main stream brand). They have 48v @ 4000watts and you can double up to get 48v@8000watts if you want.

See page 51 - it shows
HBCO (Hi Battery Cut Out) of > 67.6v ... 67.6/16 = 4.225, so it would let you use 100% of your battery.
LBCO (Low Battery Cut Out) down to 40v (adjustable).

My personal recommendation would be to go with something like this - that gives you full options.

For example, my design is geared for XX kwh(on average) out of my battery bank - this is needed to balance PV input vs load so I don't loose any PV power. I do this on averagein the range of 3.9v/cell hi and 3.54v/cell low. As my battery degrades, I will need to increase the range to maintain the same XX kwh. I plan to go all the way to 4.15v near the end-of-life of the battery to use it all up! So in your case, I would suggest that (as you originally posted) you find equipment that gives you the full range of options.

The other track - of using relay to control inverter on/off is still valid.
Click to expand...
If I was going to use my system as offgrid everyday I could see buying a magnum or similar inverter. Im only going to use it if theres a power outage or if shit hits the fan. That being said I really should be getting more out of my battery, so since the aims (800$ for the 2000 watter) wont allow me to use my batteries at 65.6v. I think Im going to keep looking for a comparably priced inverter that will take 65.6v..
 
FYI - I looked up SMA Sunny andOutback (other main-stream inverters) and the 48v FXR model has 68vdc max input. In the relm inverters that I've seen in a lot in posts and youtubes....
- Reliable, AIMS, MPPSolar, SMA Sunny are to low.
- Magnum and Outback look promising.

I'll be interested to read what you decide :)
 
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