Video Request for Will Prowse? Regarding EG4 18KPV Hybrid and Smart Load Function

[girfold]

Is there a video request topic for Will we can post to? I know he's said before that he really only makes videos when the community is interested in something. I know he'd do a very well and in-depth demonstration of its uses and pitfalls is the main reason I ask.

My main draw on whether or not I would start saving up to purchase the EG4 18KPV Hybrid is on use of the Smart Load feature on page 55 of the manual: https://eg4electronics.com/backend/wp-content/uploads/2023/04/EG4-18KPV-12LV-Manual-1.4.4.pdf

I'd be interested in basically pre-cooling/heating a room with a mini split when SoC is high and there's a significant PV input.

My main worries are:
* Cloud impact to this load? It has this mention below (in italics). My worry is that if clouds move in and out frequently then you'd often be going from >1000W down to sub 1000W frequently - a Mini-split connected to this output could be flipped on/off too frequently and impact the electronics?
"When the PV power exceeds 1000W, andthe battery system SOC gets to 90%, theSmart Load Port (GEN) will automaticallyswitch on to power the connected load.When the battery reaches SOC<85% orPV power<1000W, the Smart Load Portautomatically switches off."
* The manual doesn't specify that this would be an inverted AC load, and what voltage it would use? Can it be set to 120V only or 240V?

Thanks!

 

[timselectric]

It would be an inverted output. As it's designed to use the PV as the power source.
And the output is 120v/240v split-phase.
So your loads can be 120v, 240v, or any combination of both.

 

[girfold]

It would be an inverted output. As it's designed to use the PV as the power source.
And the output is 120v/240v split-phase.
So your loads can be 120v, 240v, or any combination of both.

Thanks! That's definitely pretty useful then. I could see running a pump / water heater / ac with this, but would be worried about the potential frequent on/off switching when there's cloud cover. I know water pumps are usually ok with frequent on/off (at least the DC ones are), what about something like a water heater for this load?

 

[timselectric]

Thanks! That's definitely pretty useful then. I could see running a pump / water heater / ac with this, but would be worried about the potential frequent on/off switching when there's cloud cover. I know water pumps are usually ok with frequent on/off (at least the DC ones are), what about something like a water heater for this load?

A standard water heater (heating elements) would be fine. But the new heat pump type has a compressor. And wouldn't like power cycling.

 

[SignatureSolarJames]

hmm, we ought to crank one out, thanks for the feedback

 

[girfold]

hmm, we ought to crank one out, thanks for the feedback

Thanks! In the video, mind going over concerns of cloud cover (feature turning on and off if it's a partly cloudy day) and how certain electronics would be less ideal for this type of use case? Maybe even going over the types of equipment that would be less prone to damage when using this functionality?

I always envisioned having a standalone PWM charge controller for this kind of purpose and having this feature seems awesome, but want to know what it's ideal for and all the good/bad scenarios that could come from using it.

Example: Probably wouldn't want people to mine crypto using this feature since a hard shutdown of the computer could cause issues when a few clouds show up.

 

[TomC4306]

Well, you do have a battery.
The battery is the buffer for clouds.
You're just talking about adding another load. I think if properly implemented, from a distance it seems as though it would work.
I don't understand why you think things would be power cycling.
Or put a timer on the output so that it Powers the load for a minimum amount of time.

 

[girfold]

Well, you do have a battery.
The battery is the buffer for clouds.
You're just talking about adding another load. I think if properly implemented, from a distance it seems as though it would work.
I don't understand why you think things would be power cycling.
Or put a timer on the output so that it Powers the load for a minimum amount of time.

That's right, there's a battery for all the normal loads, but curious about the output GEN load per the statement here in the manual:

"When the PV power exceeds 1000W, and the battery system SOC gets to 90%, the Smart Load Port (GEN) will automatically switch on to power the connected load. When the battery reaches SOC<85% or PV power<1000W, the Smart Load Port automatically switches off."

You could be getting good sun with 3000W input, then a few clouds come over for a few minutes that drops it to 300W, then afterwards would come back to 3000W. For a dumb water heater, this probably isn't a problem - just stops heating the water for those few minutes, then gets back to work once the clouds clear.

We could probably set the PV input to something low where even cloud cover won't impact it as long as we're above 85% SoC, like 50W setting to reduce the bouncing of that GEN load. That way, at night or several cloudy days, it's not going to eat the battery as a non-essential load.

I do want the load to power off before draining the battery below 85% as is the purpose of the Smart Load function, but I'm interested in the real world results of this functionality.

 

[timselectric]

Hopefully it has a time delay function.
So that it can carry through intermittent cloud cover.

 

[TomC4306]

How small is your battery on an 18K PV?
If your battery state of charge drops that fast with an extra 1000 watt load, your battery is too small.
When inverting, the inverter circuit is powered from the high voltage DC bus. Battery is connected to this bus and the mppt are also connected to this bus.
There is no switching per se on the DC side. The switching happens on the AC side, grid input.

Is this smart load port an AC output or a relay output?

 

[timselectric]

How small is your battery on an 18K PV?
If your battery state of charge drops that fast with an extra 1000 watt load, your battery is too small.
When inverting, the inverter circuit is powered from the high voltage DC bus. Battery is connected to this bus and the mppt are also connected to this bus.
There is no switching per se on the DC side. The switching happens on the AC side, grid input.

Is this smart load port an AC output or a relay output?

It's an AC output. Controlled by the two parameters.
This function doesn't use battery power.

 

[girfold]

How small is your battery on an 18K PV?
If your battery state of charge drops that fast with an extra 1000 watt load, your battery is too small.
When inverting, the inverter circuit is powered from the high voltage DC bus. Battery is connected to this bus and the mppt are also connected to this bus.
There is no switching per se on the DC side. The switching happens on the AC side, grid input.

Is this smart load port an AC output or a relay output?

This would be a Smart Load Port. SoC is not the concern as much as the other criteria: PV power<1000W

PV Input power needs to be in excess of a defined value in the settings. In their example, 1000W of PV input power. Basically, it's meant for a scenario where you've got a high SoC and you're steadily receiving Solar Input, so you know that you can start powering a separate load. This is awesome and ideal for making the most out of your solar array in off-grid living, as with grid-tied, you could just export extra energy. In off-grid it could heat water, pump/aerate a pond, distill water, or some other non-essential loads that are convenient to have when your batteries are full but the sun is still blasting.

 

[WarmPepsi]

Maybe have a variable to make that auto-shut off an "And" rather than an "or". or even better yet...

You may not care if your batteries are at 95% and you have say 3kw PV to run an aux load... but if the PV drops for some duration; say...5-10 minutes, maybe then it kicks off? Battery is still above the 85%, but it's not an instant cut off....

Just suggestions.