Sol-Ark 15k Current Capabilities

[Lt.Dan]

Just wanted to bridge this off of the Midnight Solar thread to keep it tidier.

I get where you are coming from on the 275A rating (vs. 250A or 210A etc.), But has anyone done long term amp tests on Sol-Ark 15K and/or Eg4 18K? I have heard that on charging, the 15K is quickly derating charge current to less than 275A due to temps. In fact one person that I know with a bit of 15K experience (dealer with SA15K in their showroom, fully off-grid) looked at me as if I was joking when I mentioned 275A of charging from a 15K.

I would imagine discharge amps would end up with similar results to charge amps, as far as temp derating goes.

Forgive me if this has been discussed in other posts ion the forum. I didn't even check.

Another thing to consider, as far as kW of output. Despite the fact that it's possible to run 17s configuration to gain on output, the ratings need to be based on "normal" installs. And 17s will not be a "normal" install. Any "48v" LifePo4 battery that someone buys "off-the-shelf" will be 16s. And as such, ratings NEED to be based off that.

I agree with @timselectric that you should not need to manipulate things to get nameplate ratings!

It all gets a little fuzzy with an AIO, because of how the flow of power is inside of them. But at the end of the day, whatever the nameplate says, should be "nominal output", eg: output capability under worst case scenarios, NOT best case scenarios, let alone "unique/custom" scenarios!

I have stressed tested the Sol-Ark 12k at max capacity for a year or so, and it definitely had heat problems. Hence why I updated to the 15k. I have not had a heat related issue since the switch. Temps stay under 60*C almost all the time.

But to really test that, I want to run it tonight, and dump power back to the grid at max sell-back power, to deplete my battery bank entirely. This will let me test 2x things;

1) Temps, we'll see how much they rise, and if they become a problem,
2) True Output Current, and for how long max current can be held.

I can post the charts from Solar Assistant showing Current (A) and Wattage (W), from a full battery, to dead.

The naming scheme has been beaten like a dead horse. I'll leave it at that. Everyone has their opinion, and we all know what opinions are like...

Should be fun though

 

[DIYrich]

My basement gets warm dumping 6kw to the grid for 5 hours using a 15k (energy storage incentive from the utility).

 

[Lt.Dan]

My basement gets warm dumping 6kw to the grid for 5 hours using a 15k (energy storage incentive from the utility).

I've had the mini-split/heat pump in my garage off for a while, and its been under 60* in the garage for the last few months. I could also crank the heat in there, get it up to 80-90* to better simulate temps.

 

[Cmiller]

Just wanted to bridge this off of the Midnight Solar thread to keep it tidier.


I have stressed tested the Sol-Ark 12k at max capacity for a year or so, and it definitely had heat problems. Hence why I updated to the 15k. I have not had a heat related issue since the switch. Temps stay under 60*C almost all the time.

But to really test that, I want to run it tonight, and dump power back to the grid at max sell-back power, to deplete my battery bank entirely. This will let me test 2x things;

1) Temps, we'll see how much they rise, and if they become a problem,
2) True Output Current, and for how long max current can be held.

I can post the charts from Solar Assistant showing Current (A) and Wattage (W), from a full battery, to dead.

The naming scheme has been beaten like a dead horse. I'll leave it at that. Everyone has their opinion, and we all know what opinions are like...

Should be fun though

Awesome! I look forward to seeing those results!

 

[Lt.Dan]

Alright the results are in! And they are pretty boring.

Now I want to preface this. I am not looking at the far right "Batt" column except for the current, even though it makes the inverter look better per say. The number to look at is at the top, front and center, under INV. This is the number that you will ACTUALLY get, to the breaker panel, at full load. Now the battery started at somewhere around 52.5v, and like 97%, because it had already been discharging at 7kw for a few minutes before I intervened and maxed it out. Room temp was around 78*F. I didn't have enough time to heat up the whole garage.

4:11PM - Just started. ~269a, and 13584w out. Temps are low, 45.5C, since it just started.



4:18PM - Only 7 min in, and the temp has risen to 55.4C. This was worrying. Current is 270a.



5:20PM - Over an hour later, temp is 62*C, and the highest I ever saw it. Current is 272.6a, and this is the highest I saw it get, but battery voltage is starting to drop a bit, and Inverter power is 13041w.



6:07PM - Almost another hour later, temps are varying between 58-61*C. Current is holding steady at 272-272.5a. Inverter power still over 12,000w, 2 hours in.



6:31PM - Voltage is dropping faster.



6:45PM



6:52PM, we are finally under the 12kw rating, at 46.91v. Still chugging along though at 272.7a.



6:55PM - Finally reached disconnect on the first battery, end of test. Just under 3 hours of MAX CONTINUOUS LOAD.



I will note, the fans ran for another 7 minutes before they turned off completely. During this test, the 1 time it hit 62*C, the fans did ramp up, idk if it was max speed or not, but they did ramp up, quickly bringing it down to 60*C, and the fans turned back to their normal operation after a couple minutes. I even got a video of the noise level, which was very manageable, and nowhere near louder than a conversation.

 

[Cmiller]

Alright the results are in! And they are pretty boring.

I would say those are pretty nice results! It held right around 270A continuous for nearly 3 hours. And also the way it sounds, the fans were easily able to manage the heat, so no worries on temps getting higher than that 60C.

Thanks for this test!

 

[Lt.Dan]

I would really like to see others do something similar with other inverters! Maybe I can change this thread title to "Invert Stress Test Results". I'd love to see the popular ones too. EG4, Victron, Voltronic, and others!

 

[2TrevorJ]

Works fine on the charging side too. 530A charging spread over two 15K's.

18.0 kW from Solar
14.2 kW from Grid
27.3 kW to Battery Array
3.4 kW to Household Loads

Of course it's kinda difficult to sustain charging that hard for hours.

I wonder if the 12000W battery powered AC output on the 15K's spec sheet might be underselling a bit to cover for 15S battery setups like my HomeGrid. They are a battery partner after all and the spec sheet would need to account for it or the complaints would flow. While initial (resting) voltage is ~49.3V voltage nosedives from 47.8V at 9% SOC to as low as 45.5V or so when loaded down at 5% SOC. 12.5 kW potential...like 850W lower than a 16S setup @ 275A.

 

[Zwy]

This test is mainly dumping power to the grid?

I'd like to see if it could handle inductive loads at high amps like I would see in my shop running motors 5hp and larger. Anyone do a test like that?

 

[Lt.Dan]

This test is mainly dumping power to the grid?

I'd like to see if it could handle inductive loads at high amps like I would see in my shop running motors 5hp and larger. Anyone do a test like that?

Yes this is roughly 3kw to the house, and the rest to the grid. This enables the inverter to perfectly balance Leg 1 and Leg 2 also, as you can see different amounts of energy going back to the grid under the "Grid" column, where Leg 2 is much higher.

I don't have any high inductive loads like that, other than my home AC and 240v Welder. Let me look around and see what I can figure out...

 

[muaddib721]

Great test... thanks for putting in the time to do that for all of us solar junkies. I love my two 15ks... runs my whole house without any issues. I'm working on setting up a long term, real life, day to day test to compare the 15k to the 18kpv. Working on getting the materials to tweak my current setup to include the 18kpv so that I can switch between the two.

 

[Lt.Dan]

Great test... thanks for putting in the time to do that for all of us solar junkies. I love my two 15ks... runs my whole house without any issues. I'm working on setting up a long term, real life, day to day test to compare the 15k to the 18kpv. Working on getting the materials to tweak my current setup to include the 18kpv so that I can switch between the two.

Just buy the house next-door and install the 18kpv there. Direct comparison! Lol

 

[G00SE]

Great test... thanks for putting in the time to do that for all of us solar junkies. I love my two 15ks... runs my whole house without any issues. I'm working on setting up a long term, real life, day to day test to compare the 15k to the 18kpv. Working on getting the materials to tweak my current setup to include the 18kpv so that I can switch between the two.

This is gonna be exciting to see
@Lt.Dan thanks for posting the results. While I too am curious about induction loads, it is still refreshing to see these things functioning for long durations a busting myths about AC output capacity
I’ll try and emulate in a much poorer version soon

 

[mikecogs]

A question for everyone here: The Sol-Ark Spec sheet says 62.5A max output with PV (50A battery only). If the grid goes down, and you are running off battery at night, you are limited to the 50A, correct? Does the 160A, up to to 275A battery charge/discharge, only hit those amps when the grid is up? Also, what happens if the Sol-Ark is setup as whole home, so it goes electric meter, Sol-Ark, main panel, and the Sol-Ark fails while the grid is up? Do you still get the 200A pass through or are you dead unless you have a bypass?

 

[Lt.Dan]

A question for everyone here: The Sol-Ark Spec sheet says 62.5A max output with PV (50A battery only). If the grid goes down, and you are running off battery at night, you are limited to the 50A, correct?

I would ignore the AC output current rating. You are limited to 275a (DC) discharge like posted above. So dependent on your battery voltage will vary what you are going to get.

Does the 160A, up to to 275A battery charge/discharge, only hit those amps when the grid is up?

Im not sure what you mean by 160A, but no, you get the full 275a when the grid is up or down.

Also, what happens if the Sol-Ark is setup as whole home, so it goes electric meter, Sol-Ark, main panel, and the Sol-Ark fails while the grid is up? Do you still get the 200A pass through or are you dead unless you have a bypass?

This I'm not sure on, I'm guessing it depends how the unit fails. If nothing turns on/no response, then you are dead. But maybe with a small internal failure like the MPPT died, then you can still failover to grid i'm sure.

This is why it is always important to have bypass/backup plans.

 

[a619]

You definitely want to have a manual transfer switch in case you ever need to remove inverter for repairs.

 

[DIYrich]

A question for everyone here: The Sol-Ark Spec sheet says 62.5A max output with PV (50A battery only). If the grid goes down, and you are running off battery at night, you are limited to the 50A, correct? Does the 160A, up to to 275A battery charge/discharge, only hit those amps when the grid is up? Also, what happens if the Sol-Ark is setup as whole home, so it goes electric meter, Sol-Ark, main panel, and the Sol-Ark fails while the grid is up? Do you still get the 200A pass through or are you dead unless you have a bypass?

62.5A is the Inverter limit (DC-> AC).
The 50A is based upon 275A at a minimum battery voltage. I routinely push 14,000 watts (58 amps) off the battery. In fact, if you build a 17s battery, you can push the full 62.5A with a 54.6v battery.
I believe when the Sol-Ark is off, it passes through Grid Power. It is possible that certain failures would take you off grid.

 

[DIYrich]

Im not sure what you mean by 160A, but no, you get the full 275a when the grid is up or down.

160a is only if you have one of the battery connections. When you have both battery connections, the limit is 275a.

 

[mikecogs]

I would ignore the AC output current rating. You are limited to 275a (DC) discharge like posted above. So dependent on your battery voltage will vary what you are going to get.

Im not sure what you mean by 160A, but no, you get the full 275a when the grid is up or down.

This I'm not sure on, I'm guessing it depends how the unit fails. If nothing turns on/no response, then you are dead. But maybe with a small internal failure like the MPPT died, then you can still failover to grid i'm sure.

This is why it is always important to have bypass/backup plans.

Thanks for the reply. The 160A is on page 13 of the manual "If only one set of terminals is used, the max battery charge/discharge will be limited to 160A."

 

[Lt.Dan]

Gotcha. I forgot about the 160a limit on 1 DC leg. It's been a while since I had to deal with that lol