Maximizing PV (Solar) Usage When Connected to Shore Power

[howson]

I have yet to make an introduction post describing my 376TH, the huge systems, all the modifications, etc. so I will have to do that soon enough, but I answered what I could in bold red text above.

Steven

I am looking forward to reading that post and thank you for the pictures. Please start a new thread when you create the introduction so it gets seen by everyone. This thread has limited applicability to most here on the forum. Even the regulars on the Facebook group (I saw your post--there's very knowledgeable folks in that group!) haven't engaged on this topic as I'd hoped.

[howson]

FiveStarNomadic

DVCC, as you noted, is not required with the Battle Born and ESS Assistant. I misinterpreted the chart in Victron's manual (after Battle Born wouldn't provide me with a definitive answer on whether their battery was "intelligent" or "normal" --using Victron's terminology).

The ESS Assistant in the Multiplus and CCGX is working with DVCC turned off, so I'm leaving it that way until I learn of a reason to have it on. (My settings are shown below).



Readers may want to note that if they have the ESS Assistant set to "Keep Batteries Charged" DVCC must be on (at least according to the CCGX manual ver .03, par 8.6).

[MichaelS]

Hi howson

I am in the UK and have a European motorhome, a Morelo Palace Liner. My first motor home was a Country Coach a stunning RV but too large for touring the UK and Europe. I share this out of politeness as I have no legitimate reason to be on this forum, other than I landed on your thread via Google, you have done exactly what I am trying to achieve. I have had several Victron systems over the years and now have a Multi, smart shunt, Cerbo GX with a MPPT 150/85- MC4 VE.Can. 4 off Super B lithiums etc. I think I have assimilated the skeleton of your progress, and have watched your evolution through the posts and your updates specifically inserted circa 10th March, but I am unclear on the final settings you adopted. Which of your posts do you believe provides the accurate detail? I know its cheating and benefiting from your efforts but I wanted to start my testing from your confirmed final working settings.

Thank you in anticipation

Michael

[howson]

Hi howson

I am in the UK and have a European motorhome, a Morelo Palace Liner. My first motor home was a Country Coach a stunning RV but too large for touring the UK and Europe. I share this out of politeness as I have no legitimate reason to be on this forum, other than I landed on your thread via Google, you have done exactly what I am trying to achieve. I have had several Victron systems over the years and now have a Multi, smart shunt, Cerbo GX with a MPPT 150/85- MC4 VE.Can. 4 off Super B lithiums etc. I think I have assimilated the skeleton of your progress, and have watched your evolution through the posts and your updates specifically inserted circa 10th March, but I am unclear on the final settings you adopted. Which of your posts do you believe provides the accurate detail? I know its cheating and benefiting from your efforts but I wanted to start my testing from your confirmed final working settings.

Thank you in anticipation

Michael

Yes, this is a Grand Design Owners' Forum but hopefully my fellow moderators will give me a bit of slack. We could always take this conversation "offline" (via private messages) if I get any objections.

To your questions.

DVCC is off. I'm still not quite 100% sure what it does, but either on or off it doesn't seem to have any affect on my specific system.

For ESS I currently have it set to "Keep batteries charged" as I have found little need to plug into shore power while at home. The solar panels keep the batteries charged, even though I leave my Victron inverter and Winegard 360+ WiFi Gateway on 24/7. I now run the camper's dehumidifier during the day when there's plenty of solar power available, so no worries about that device either. If there's even a possibility of running an air conditioner I plug into shore power.

If I was on shore power, I'd have ESS set as shown below Optimized (without BatteryLife) with a Minimum SoC of 50%. I can't defend the 50% setting--purely a "feels right for me" number.

As I'm sure you know at this point, the settings as set below will utilize solar and batteries first until the SoC reaches 50% and then shore power will kick in as needed to recharge the batteries and supplement any loads.




I'm still learning, so if you discover something I've overlooked or there's a better way, please do me the favor of posting an update.

[openrangeowners]

Howson - you mentioned an issue with ESS - could the following have something to do with this?

From AMSolar (if using an SPS ...)
SPS Clicking - The SPS will begin to click when either the AC load is overloading the inverter, or the AC source isn't strong enough to supply the power you need. The SPS will cut out with a weak shore power source less than 103V AC. Dynamic Current Limiting and UPS mode will also cause this to happen. If you are using an air conditioner without an Easy Start this will also likely occur.

[MichaelS]

Thank you for your explanation, it is truly as simple as I thought (after your in depth investigative effort an easy call) but I was in the woods and could not see the trees! I will certainly keep you updated, I had already started a debate with the senior tech at the UK distributor whom I have dealt with in the past and have been waiting for him to respond when I found this.. The one thing I did not get from your thread which you have made clear here was the need to change settings dependent on shore power. It is similar to setting a lower float voltage on the Multi and the correct one on the MPPT which achieves prioritising the solar to a degree. But I will go play for a bit and come back with anything even if its nothing. Thanks again for your prompt feedback.

Regards

Michael

[howson]

Howson - you mentioned an issue with ESS - could the following have something to do with this?

From AMSolar (if using an SPS ...)
SPS Clicking - The SPS will begin to click when either the AC load is overloading the inverter, or the AC source isn't strong enough to supply the power you need. The SPS will cut out with a weak shore power source less than 103V AC. Dynamic Current Limiting and UPS mode will also cause this to happen. If you are using an air conditioner without an Easy Start this will also likely occur.

I've never experienced the symptoms described by AMSolar. I don't remember posting the note above or referencing the issue...but I don't remember everything.

The Progressive Dynamics EMS-50 installed in my trailer will shut off shore power if it falls below 104vAC. I've never experienced a low (or a high) voltage issue.

AMSolar's reference to an "inverter" could be anything from a Harbor Freight special to a top-of-the-line Magnum or Victron. I've intentionally overloaded the Multiplus 3000 in my unit and the AC output voltages never lagged low enough to cause a concern--certainly didn't cause an issue with the SPS. (Consider the Multiplus is putting out just over 25A max through two circuits wired for 50A each--the circuit won't have an issue power.)

[howson]

bertschb

As requested I've started looking at the ESS (again) to try and document the benefit and how to get it.

Let me start by writing that this will limited to the results based on the settings. I'm not going to get into how to load the ESS Assistant in the Multiplus. Victron has plenty of information on how to load an Assistant. https://www.victronenergy.com/live/ess:start

Let me also emphasize again that neither Victron nor AMSolar recommend or support running the ESS Assistant in an Off-Grid system that can be connected to shore power. (They believe it may be possible to inadvertently backfeed the power grid--a no no. Backfeeding is not possible in my setup for many reasons I won't belabor here--just be aware that this is an unsupported setup.)

Part 1: Why ESS?

What you'll see in this post is a screenshot of the settings as displayed on my CCGX (Color Control GX) and the actual flow of power as also shown on the CCGX for a given setting. There's a note explaining what's going on at that time.

NO ESS ASSISTANT

The ESS configuration is changed on the CCGX under SETTINGS > ESS.

With a battery state-of-charge <100% and shore power connected, as currently configured without the ESS Assistant the batteries attempt to charge as quickly as possible from all possible power sources. I don't prefer this method because there is (normally) plenty of solar power (PV) available during the day to charge up my batteries. If the batteries charge quickly from shore power, PV available later in the day is not utilized--a waste. As you'll see later this is similar to the ESS Assistant mode Keep Batteries Charged.



ESS Assistant Loaded, Mode = Keep Batteries Charged

There are four ESS modes: Optimized (With Battery Life), Optimized (Without Battery Life), Keep Batteries Charged and External. I use Optimized (Without Battery Life) and Keep Batteries Charged depending on my usage scenario. (Battle Born batteries don't need the "with battery life" configuration as their Battery Management System (BMS) takes care of itself. I don't remember what "External" is used for--there's info in the ESS manual if you're curious.)

Below is what happened with Keep Batteries Charged selected.



ESS Assistant Mode Optimized (Without Battery Life)

In the picture below the Minimum SOC (unless grid fails) means that PV will be utilized to recharge the batteries (and support AC Loads and DC Power requirements) before tapping Shore power. Since the Minimum SOC setting is 25% and the battery SOC is 51%, the PV Charger is providing almost all the power to the trailer. The 45W from Shore will be explained shortly.



Shore power will stay at or near 40W because of the Grid setpoint shown below if there is Shore power available and if the battery SOC is above the Minimum SOC (unless grid fails) setting.




ESS Assistant -- ESS #1

ESS #1? That means the SOC is low per the Victron ESS manual. An example shown below. Note the settings that triggered ESS #1




There's more but this is all for this post.

Howard

[howson]

bertschb

Part II of Why ESS?

In all the scenarios in post 53 PV was being utilized, but in some cases not leveraged to it's maximum since shore power (if allowed) would quickly charge the batteries and then available PV is left untapped. Even worse, without the ESS Assistant when the batteries are full PV is ignored if Shore is available.

In the graphic below the ESS Assistant is not loaded, Shore power is available, and the batteries are at 100%. A residential refrigerator and a dehumidifier are running thus there's ~450W AC Load going through the Multiplus. Note the PV Charger's output is 0 even though the sun is shining and it's nearly noon. This is not good--especially when the Shore power being consumed is paid for by yours truly!



The pic below was captured moments later after reconfiguring the Multiplus with the ESS Assistant. Now the PV Charger is providing all the power to the trailer and the only money I'm paying to Gulf Power is the amount to keep the 30W Shore line "awake". (The refrigerator compressor may have kicked off thus the lower AC Load.)

What you see below is why all the time and effort to learn about the ESS Assistant was worth it (to me).





Below is with just the residential refrigerator running and a few odds and ends in the trailer. The PV Charger is taking care of business and providing all the power.



So now let's discuss what happens when the sun goes down.

Obviously PV will drop to 0 but the residential refrigerator will still draw power. Currently my system is configured as shown below. The Minimum SOC (unless grid fails) percentage I've chosen is arbitrary--easily could be different as desired by each user.



So what does this all mean? How will the system react when the sun goes down?

What will happen is the battery bank will supply power to the inverter for the AC Loads until the battery SOC reaches 45%. Then Shore will be prioritized. (If Shore fails obviously the batteries will continue to power the trailer until exhausted.)

In the morning when the sun comes up and PV Charger power is available, power is sent to the batteries and AC Loads. As long as the batteries are charging the PV Charger output is the maximum the solar panels can generate. When the batteries are at 100% the maximum the PV Charger will generate is the AC Loads requirement (up to the maximum the solar panels can generate).

One more scenario: as you saw in post 53, if the batteries are at (or near) the Minimum SOC setting (ESS #1), Shore power kicks in to ensure the battery SOC doesn't drop further.

Head hurt yet? I hope not...

SUMMARY

Without ESS Assistant the power prioritization is:
A) SHORE
B) PV / BATTERY

With the ESS Assistant the power prioritization is:
1) Battery Bank > Minimum SOC setting and mode not Keep Batteries Charged
A) PV
B) Battery Bank
C) Shore
2) Battery Bank <= Minimum SOC setting and mode not Keep Batteries Charged
A) SHORE + PV

SO WHAT?

So how do I use the ESS Assistant in the real world?

If I'm at a paid-for commercial campground, the ESS Assistant is set to Keep Batteries Charged. No sense using my system and cycling my batteries if I've paid for electricity.

At home or "moochdocking" I use Optimized (without Battery Life). Honestly I'm still messing with the Minimum SOC--during the winter 50% was about as low as I could go and still power the minimum items in the trailer and expect the batteries to recharge during the day (with the low-in-the-sky, weak sun).

Final thought (anticipating a comment or question): Won't using the ESS Assistant and constantly charging/disccharging the Battle Born batteries wear them out? My response? I hope so! The batteries are rated for ~3,000 cycles. If I wear out the batteries (before I wear out) I'll have gotten the maximum use out of them. (If the average is one cycle per day, that's 8 years worth of battery usage! I hope my 315RLTS lasts 8 years...) The Minimum SOC could be set at 95% and use very little battery power overnight, but still maximize PV Charger power during the day (to power AC Loads) if desired.

So there you have it. Hope these two posts were informational enough without being too wordy.

Howard

[bertschb]

howson

Hi Howard

Well, I didn't get very far. I tried loading the ESS Assistant and after following the directions to disable the Virtual Switch, I tried starting the Assistant and got an error. It said Country/Grid code not selected. When I went to the Grid tab to select my country, I didn't see the United Sates - just European countries. So, I set the Virtual Switch setting back to where it was and sat back down in my chair defeated before I even really started

Maybe this is unique to the new Multiplus II?

- Brian

[howson]

howson

Hi Howard

Well, I didn't get very far. I tried loading the ESS Assistant and after following the directions to disable the Virtual Switch, I tried starting the Assistant and got an error. It said Country/Grid code not selected. When I went to the Grid tab to select my country, I didn't see the United Sates - just European countries. So, I set the Virtual Switch setting back to where it was and sat back down in my chair defeated before I even really started

Maybe this is unique to the new Multiplus II?

- Brian

Mine's set to "Other".

[bertschb]

Well, I got greedy trying to set up ESS and now my inverter (just the inverter side) won't turn on.

When I turn the inverter on, the "Inverter On" light indictor is on for 5-10 seconds then it turns off and the Charger Mains On light is on. So my inverter is charging but the inverter side of things is offline.

I ended up going back and deleting the ESS assistant and reverting all settings back to where they were. No bueno. I then reset the default settings for the inverter and just updated the battery type and charge parameters. No bueno. I shut off power at the post, shut off DC power to the Cerbo. I've tried everything I can think of and my inverter won't power up. But the charger is working.

I really didn't change much to get the ESS Assistant loaded so I'm not sure where things went wrong but at this point I'm pretty bummed and out of ideas. Everything was working so good until this.

If I was a drinking man, I'd be slamming back a cold one right now....

[howson]

Well, I got greedy trying to set up ESS and now my inverter (just the inverter side) won't turn on.

When I turn the inverter on, the "Inverter On" light indictor is on for 5-10 seconds then it turns off and the Charger Mains On light is on. So my inverter is charging but the inverter side of things is offline.

I ended up going back and deleting the ESS assistant and reverting all settings back to where they were. No bueno. I then reset the default settings for the inverter and just updated the battery type and charge parameters. No bueno. I shut off power at the post, shut off DC power to the Cerbo. I've tried everything I can think of and my inverter won't power up. But the charger is working.

I really didn't change much to get the ESS Assistant loaded so I'm not sure where things went wrong but at this point I'm pretty bummed and out of ideas. Everything was working so good until this.

If I was a drinking man, I'd be slamming back a cold one right now....

Well that sucks.

Can you take a snapshot of each tab's settings and post them?

[bertschb]

Can you take a snapshot of each tab's settings and post them?

I'll do that in a minute. I was able to turn the inverter only (no charger) on from Victron Connect. That works. But, if I try to turn the inverter On (inverter and charger) the inverter turns on then it switches to charger only mode. At least the inverter runs by itself!

[bertschb]

OK, here ya go...I can get screen shots from VE Config as well but that will take longer as I'd need to boot to Windows.