Maximizing PV (Solar) Usage When Connected to Shore Power

[howson]

Note: This post assumes the reader knows what the acronyms used mean as they were spelled out previously.

POST 1 of 2
"Do my goals result in maximum use of the system?" That's the question.

From the first post in this thread, here were the goals:
1) Do not use inverted 12v Battle Born power to run 120vAC loads when connected to shore power at home.
2) Keep the Battle Born batteries fully charged.
3) Supplement shore power with solar when available.

It dawned on me while reading Guest 's battery thread and watching Will Prowse's videos on YouTube: if the Battle Born batteries I own can charge and discharge ("a cycle") 3,000 times I could cycle them every day for over 8 years! I doubt I'll own the camper in 8 years. Was I leveraging the batteries and solar on my camper to their full potential with the settings in ESS?

Here's the setting in ESS I started with:


Below is typical day's result with KEEP BATTERIES CHARGED selected. The RED bar is the dehumidifier (and other minor components) powered in the camper. It's power being consumed. Orange is solar power generated. The difference is what is drawn from the Grid.



Here's the graph in table form:


What I did was change the ESS setting to Optimized (without BatteryLife). (I don't think "BatteryLife" applies to Battle Born batteries--see Victron's ESS Installation and Design manual for more information.) Note that the Low SOC cutoff is set to 50%. I don't want the batteries discharging past that point as experimentation has shown they won't recharge if the SOC is set lower. (I may experiment with 45%.)



Due to number of attachment limitations, see the next post for yesterday's results due to the changes.

[howson]

POST 2 of 2
"Do my goals result in maximum use of the system?" That's the question. (cont from previous post)

The result with the new settings:





Conclusion: By leveraging the storage capability of the batteries about 2.3 kwH of solar was used that otherwise would have been untapped.

But...to put this in perspective, Gulf Power charges ~.145 cents per kwH, so I saved a whopping 30 cents.


I tried to keep this short--if something's not clear or you have questions fire away.

Howard

[Guest]

Nice Howard. Your Victron system is outstanding where we need them to build a converter/charger with some of these functions. Including temperature compensation which really should not pose an issue on any battery since its just a variation on charge current. I've written Victron and suggested they consider it. I had also purchased an AIMS converter/charger that did have this functionality but with the cooling fan being on all the time I returned it. For storage, battery life will be maximized by keeping them at around 50% SOC in a cool area if possible and while being removed from ALL loads. For the in-use case we would want a charger to control SOC to 80%-20% or as Will had shown in the graphs, 75%-25%. Its nice that these concepts are finally gaining traction. Jim

[Guest]

Howard,

Your plots and tables look like a use case on your solar charging strategy. They were not visible earlier where they can be seen now. Wondering why you do not set your Victron to charge to 50% SOC from a lower state of charge, then during inactivity, open the battery switch to remove all loads from the system? Otherwise your exercising the batteries and cycling them while not using the RV and this is working away at your battery(s) longevity. Can the solar panels handle this?

Jim

[howson]

...then during inactivity...

There's never an "inactivity" time as the camper is in humid Florida. If we're home, the dehumidifier is plugged in and on. Sorry, I know that's being mean to you folks in the frozen north.

Besides, sometimes the DW & I go out and sit in the camper just for the heck of it. It's set up in the backyard so why not?

[FiveStarNomadic]

Howard, I need your expertise on getting the ESS Assistant dialed for my system. I am having a nightmare of a time getting my PV Array to be the default power supply when connected to the 50a RV plug while storing my 376TH. I simply want the grid as a backup for when the PV Array can’t keep up and I dip too far into my battery bank. Back feeding into the grid would also be nice as I am already set up with my local power company but that isn’t totally necessary.

The system is laid out with the following parts:

• 2.8kw Solar Array of 9x315w REC Solar Monocrystalline panels
• Victron SmartSolar 250/100 MPPT solar charge controller
• Dual Victron MultiPlus 24/3000/120Split Phase inverters
• Victron BMV-712 Shunt
• Victron CCGX console in coach
• Victron Autotransformer for genset (to change power signal to split phase)
• 14 Battleborn LiFePo4 batteries in a bank at 24v

I would like to pick your brain and get my ESS Assistant dialed so I can maximize the solar intake while my RV sits at home (I keep one A/C set at 82° so it doesn’t roast inside during the summer)...is that something you can guide me through?

[howson]

I am having a nightmare of a time getting my PV Array to be the default power supply when connected to the 50a RV plug while storing my 376TH.

As noted in the first post (in large red font) enabling DVCC (Distributed Voltage and Current Control) and ESS (Energy Storage System) in an off-grid system is not recommended by Victron. (See https://www.victronenergy.com/live/e...llation-manual and then When is it appropriate to use ESS?) My Victron dealer, AMSolar, reviewed the information I sent them and they refused to support or advise on any of the settings. Battle Born also declined to give any advice. (Neither had even configured a system with DVCC or ESS.) Post #9 in this thread spells this out in detail.

...is that something you can guide me through?

I make no claims at being an "expert". To date I haven't messed up my system or trashed any components, but there is always that possibility if a mistake is made. I have no experience whatsoever with a dual inverter setup. (I understand the concept but no hands-on at all.)

Bottom line: I'm more than willing to discuss what you plan on doing and providing my .02, but I don't have a pat answer for a configuration that I know will work (and continue to work). Regardless of anything discussed here or attempted you must be willing to accept 100% responsibility for the result.

Note there are also other individuals on this forum with experience messing with their Victron components--I invite and encourage them to chime in. Especially if they disagree with something I write--I'm 100% sure I don't always have it 100% right.

If you're still interested in pursuing this, let's start with some information.
1) What GD RV do you own and have this system installed in? (Oops...you noted in your post it is a 376th.)
2) Did you install this system yourself or did you have it installed?
3) List the firmware versions you're currently running in the Multiplus', CCGX, BMV, and SmartSolar controller.
4) What version of VictronConnect are you using?
5) Have you used VEConfigure?
6) Do you have an MK3-USB adapter and know how to use it?

Howard

P.S. BTW...welcome to the forum.

[FiveStarNomadic]

After I sent this post in asking for your help, I read over your posts again and again, then read the entire ESS Assistant manual over again. This morning, I went out to the RV and attempted to plug in with my Mk3 (yes I have one and know how to use it), but it shows as COM3 is available but it continually fails to connect, I’ll diagnose that later. I ended up VRM Console to download the file, then make the changes, then upload it again.

my problem last night that stumped me was simply because I forgot to make all the changes in BOTH inverters to add the ESS Assistant, so last night, the main inverter feeding power into the grid directly from the battery bank as the slave inverter (not programmed with ESS) was drawing off the grid to recharge the batteries.

So today, I finished programming both inverters, uploaded the file, and everything seems to be working perfectly.

1. PV Array is always functioning at full potential and taking priority to power the coach’s needs
2. I set the Grid Setpoint to 0W to force the grid input to standby until all other power sources can’t keep up
3. I set the Minimum SOC to 80% for now so that the battery bank (17kwh) will supply power over grid input until the bank drops to 80% SOC.
4. Since I am plugged in to a friend’s house that already has solar and the power company’s equipment with one way meter and all the other junk they require for feed-in, so I am playing with the feed-in function and things seem to be working well so far...

I still would appreciate any sort of input you may have for me...you’ve done far more testing and researching that me...

[FiveStarNomadic]

[howson]

FiveStarNomadic -- awesome!

What I don't see mentioned in the posts is anything about DVCC. Did you have to enable and configure that function in the CCGX and if so, how?

I'd also appreciate screen shots of how you have the ESS Assistant configured.

I currently do not have DVCC nor the ESS Assistant enabled as I had a failure associated with the EasyStarts in my air conditioners. To isolate the issue I removed as many variables as possible (including the ESS Assistant). Don't misunderstand--the failure was not due to anything in this thread, it was simply a part of the isolation process during troubleshooting. I'm knee-deep in another project (non-related to this one) so I haven't gotten back to configuring my system back to the previous setup.

I'm going to have to re-read my own thread tomorrow at work. If you can supply the info noted above I can (hopefully) provide a meaningful input.

I'm excited to have someone to compare notes with!!!

You've got an amazing setup...2254W out of your solar...wow.

[howson]

FiveStarNomadic

6 Sep 202 Update: DVCC is not required with the Battle Born and the ESS Assistant! See post 47 for more info.

The entry (pic below) in the CCGX's manual is why I asked about your DVCC settings.




When I spoke with Battle Born (a while ago now) they would not commit to stating if their battery was "intelligent" or "normal". As I've documented previously, AMSolar will not advise on this topic.

Edit: In paragraph 4.4.4 in the CCGX's manual it has the following statement, This chapter applies to all systems where an intelligent battery BMS is installed, and connected via CAN-bus. Note that this does not include the Victron VE.Bus BMS. The paragraph then goes on to state an intelligent BMS sends four parameters to the GX device. A Battle Born does not send any parameters to the CCGX, so my earlier interpretation is probably wrong--in the chart above now I think we can use the "Normal battery" settings, so DVCC can either be on or off.

Interested in your .02.

Howard

[howson]

FiveStarNomadic

6 Sep 202 Update: DVCC is not required with the Battle Born and the ESS Assistant! See post 47 for more info.

So expanding on post 41, I'm going to re-enable DVCC and set as noted below.

Limit charge current

• I'm not going to turn this on--the Battle Born's BMS will handle limiting the input current. Besides, any setting in the Multiplus or MPPT will override the setting in DVCC as stated in the manual.
  • In all situations, the maximum charge limit configured in a device itself, ie. the Charge current limit set with VictronConnect or VEConfigure for the Solar chargers or Inverter/chargers will still be in effect. An example to illustrate this: in case there is only an Inverter/charger in the system, and in VEConfigure is charge current is configured to 50 Amps. And on the GX Device, a limit of 100A is configured, then the working limit will be 50 Amps.

Shared Voltage Sense (SVS)

• I'm going to turn SVS on. Why not have the GX device automatically select the measured battery voltage to all the VE.Bus devices? I see no downside to using this feature.

Shared Temperature Sense (SCS)

• I'm going to turn SCS on. Why not have the GX device automatically send the temperature to all the VE.Bus devices? Again, I see no downside to this feature. For my system the temperature is measured by the sensor attached to the BMV-712's shunt.

Shared Current Sense (SCS)

• This sends the current measured by the BMV-712 to the SmartSolar MPPT. As noted in the manual, This feature only applies to systems that are not ESS, and/or don’t have a managed battery, since in both of those cases the MPPT is already externally controlled.
• I'll be using the ESS Assistant, so I'll leave SCS off.

Again...very interested in your thoughts.

Howard

[FiveStarNomadic]

FiveStarNomadic -- awesome!

What I don't see mentioned in the posts is anything about DVCC. Did you have to enable and configure that function in the CCGX and if so, how?

I left the DVCC off, I decided to isolate my changes to see what each individual change would do. I actually got the system functioning as I wanted without ever worrying about it. And to answer your later question, after spending a few days at BB (I live in Reno, NV and I am friends with Sean as well as one of heir ambassadors) helping build the batteries and learning all about the various aspects of them, You are correct in that the BBs do not need the DVCC as their internal BMS handles it all. A lot of their battery settings are going to be based on the assumption that you are using their batteries, hence being connected via BE.Bus.

I'd also appreciate screen shots of how you have the ESS Assistant configured.



I currently do not have DVCC nor the ESS Assistant enabled as I had a failure associated with the EasyStarts in my air conditioners. To isolate the issue I removed as many variables as possible (including the ESS Assistant). Don't misunderstand--the failure was not due to anything in this thread, it was simply a part of the isolation process during troubleshooting. I'm knee-deep in another project (non-related to this one) so I haven't gotten back to configuring my system back to the previous setup.

I'm going to have to re-read my own thread tomorrow at work. If you can supply the info noted above I can (hopefully) provide a meaningful input.

I'm excited to have someone to compare notes with!!!

You've got an amazing setup...2254W out of your solar...wow.

I have 2,835 rated watts of PV on the roof and have seen 2,998w before, cold SoCal morning, cloud edging, sun at a fairly low winter angle. My system is built for me to live and work off-grid indefinitely (except for LP, gasoline, water and waste tank capacities) because I live on remote dam sites all over the west coast for work. Also why I have 14 of the BBs in the bank (plus one of the 50ah BBs to start my Genset).

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

[FiveStarNomadic]

More screenshots of settings.

[FiveStarNomadic]

I also have some screenshots of the CCGX from settings today...