21 minutes ago, Erastus said:

These tools can't tell you much if you can't monitor the 1.XV cell.

It's main job is to count Amp-hours in and out of the battery and calculate the real state of charge (instead of relying on voltage, which is a poor measure). Additionally it can also monitor the midpoint of the battery and raise an alarm. People usually combine the BMV with midpoint monitoring and a balancer to keep the cells at the same voltage. If you use Victron balancers, they do have alarm outputs that activate if things go completely out of wack.

So a inverter does not do that automatically?  I would have thought is part of the inverter function. Thanks for your input. What % does it allow to ensure that Iout == Iin ? Is it programmable?

Edited September 19, 20187 yr by Erastus

45 minutes ago, Erastus said:

So a inverter does not do that automatically?  I would have thought is part of the inverter function. Thanks for your input. What % does it allow to ensure that Iout == Iin ? Is it programmable?

The inverter attempts to do that, but are way out. This unit is fully configurable. In conjunction with battery balancers, its the best you can do to protect your investment.

58 minutes ago, Erastus said:

I understand but a superimposed IxV curve does all of that for you.

I don't think you understand. Here is a Youtube video made especially for me when I was a newbie . 

 

1 minute ago, Chris Hobson said:

I don't think you understand. Here is a Youtube video made especially for me when I was a newbie . 

 

I X V = R

4 minutes ago, Chris Hobson said:

... when I was a newbie ...

I don't think Erastus is a newbie. :-)

Waiting to see where he is going with all the questions.

1 hour ago, Erastus said:

So a inverter does not do that automatically?

Some do, some don't, and in some setups it's not enough.

An Axpert doesn't properly count Ah in and out, even though it has all the hardware it would need to do it.

A Victron inverter does it properly, but only if it is made aware of all the charging sources, so if there are external solar chargers you also need a Venus device (CCGX etc) to tie them all together.

If you have any DC loads, then the best way to do it is add a BMV, a dedicated device to accurately measure it.

The BMV is also very popular in setups where there is no inverter: Campervans and caravans for example.

2 hours ago, Erastus said:

I X V = R

Nope.

R=V/I, quite a big difference in your result!

3 hours ago, Erastus said:

What % does it allow to ensure that Iout == Iin ? Is it programmable?

I think what you're asking here is how it determines that the amp-hours that left came back in. It is indeed programmable. You can set both the charge efficiency and the peukert coefficient.

4 hours ago, Erastus said:

Do you have a current graph and PVvolts graph for a normal day of charge for the batteries when you have a clear day?

nope 

call me stupid but here i am again.

most of my problem seems to have been addressed in this thread.

just the following; most if not all loads like the kettle kick in at high consumption, so if my system reverts to grid on that happening, although i have enough power in the batteries and pvs by virtue of the system 'lag' [which is more than a lag as the switching back takes about 5 minutes], and one of the culprits seem to be the rule 

23 hours ago, Chris Hobson said:

The voltage sag is inversely proportional to the Ah rating of your battery bank.

the real solution does not necessarily lie in better monitoring equipment but in one of two, number one seemingly the preferred one:

1. get a better inverter
2. get more batteries
3. get a gadget [unknown?] which will gradually increase the load of white goods [my kettle happens to be white ] in order for the system to cope with the lag.

as the number one option is ironically maybe even the cheaper - as it will also solve stuff like the coct's sseg regulation problems, it seems the way to go, not? 

8 minutes ago, gabriel said:

get a better inverter

When you run the Victron inverter in switching mode -- so it is like an Axpert -- you can tell it how many seconds the low-voltage condition must persist before it should switch back to the grid. This would have been perfect in this case. You could have specified that it should only switch if the low voltage condition exceeds the time it takes to boil a cup of water for tea :-)

1 minute ago, plonkster said:

you can tell it how many seconds the low-voltage condition must persist

three questions :

1. how long can this override be set on the victron
2. will this low voltage 'override' have an influence on the battery warranty
3. is frequent switching as in the 'kettle case' detrimental to a battery or does it in fact protect it

 

41 minutes ago, gabriel said:

how long can this override be set on the victron

I've never tried, but I know mjlorton (youtube vlogger), back when he was still in Cape Town, had his set to 7 minutes because that's how long it takes for the kettle to boil :-)

It can do significantly longer than 7 minutes, but I'm not sure how much more. Still, that ought to be enough for anyone? :-)

Also the Victron inverter can talk to your BMV and use the SoC to switch rather than the voltage.

43 minutes ago, gabriel said:

will this low voltage 'override' have an influence on the battery warranty

The Battery will still disconnect everything if you overdo it. Your final line of defense is always in the BMS in the battery.

44 minutes ago, gabriel said:

is frequent switching as in the 'kettle case' detrimental to a battery or does it in fact protect it

Weeellll.... you could argue that you're putting the battery through "micro cycles" and some people get terribly upset about that, but I don't see any reason to be concerned.

5 minutes ago, plonkster said:

Also the Victron inverter can...

the hunt is on!

Just now, gabriel said:

the hunt is on!

If you're defecting, then you'll likely be going to an ESS system, which is a hybrid setup that doesn't switch causing all of this to be somewhat moot :-)

i won't go to the ess system, it exceeds my needs and budget - by the looks of it.

i will have to look at another 3-4kva option.

4 minutes ago, gabriel said:

i won't go to the ess system,

No, you are going ESS.

You will drop me a PM telling me to help you source the parts you need and we will do that together.

Why? Because you will get quotes, then I will show you where to buy what.

Then we will use THIS forum to teach each other HOW to configure the ESS setup, so that Victorn SALES people can learn what users want. ;-)

2 hours ago, The Terrible Triplett said:

No, you are going ESS.

You will drop me a PM telling me to help you source the parts you need and we will do that together.

Why? Because you will get quotes, then I will show you where to buy what.

Then we will use THIS forum to teach each other HOW to configure the ESS setup, so that Victorn SALES people can learn what users want. ;-)

OK, I have to ask, what is ESS?

Never mind, I found this on Victron site

"What is ESS?

An ESS (Energy Storage System) is a grid-tie installation, incorporating solar and battery-storage, which behaves as though it were an off-grid installation …thereby enjoying the best of both worlds."

Edited September 20, 20187 yr by Antony

5 minutes ago, Antony said:

OK, I have to ask, what is ESS?

Here you go: https://www.victronenergy.com/live/ess:design-installation-manual

In a nutshell, the part that I grabbed from it: I save a lot of money! Batteries kept "alive" in case of power failures.

No seriously: An ESS (Energy Storage System) is a grid-tie installation, incorporating solar and battery-storage, which behaves as though it were an off-grid installation …thereby enjoying the best of both worlds

 

8 minutes ago, Antony said:

OK, I have to ask, what is ESS?

Never mind, I found this on Victron site

"What is ESS?

An ESS (Energy Storage System) is a grid-tie installation, incorporating solar and battery-storage, which behaves as though it were an off-grid installation …thereby enjoying the best of both worlds."

"

When is it appropriate to use ESS?

Use ESS in a self-consumption system; a backup system with solar, or a mixture of both: For example you can use 30% of the battery capacity for self-consumption, and keep the other 70% available as a backup in the event of utility grid failure.

Optimizing self-consumption:

When there is more PV power than is required to run loads, the excess PV energy is stored in the battery. That stored energy is then used to power the loads at times when there is a shortage of PV power.

The percentage of battery capacity used for self-consumption is configurable. When utility grid failure is extremely rare it could be set to 100%. In locations where grid failure is common - or even a daily occurrence - you might choose to use just 20% of battery capacity and save 80% for the next grid failure. African countries for example."

4 minutes ago, Antony said:

African countries for example.

No it is for real, all jokes aside. Sold my Phoenix inverter to a guy in Zimbabwe, to run his computers and big printer - he does designing.

The smaller one I have, another Zim guy is looked at it. Wants to power his radio and a few other small things.

Africa needs power, and solar is the way to go BEFORE they go and install large girds like SA. Decentralize the grid now, and go solar.

21 hours ago, The Terrible Triplett said:

teach each other HOW to configure the ESS setup

It would be nice if the ones who were helped can again help others... :-) They know who they are... :-P

As for myself, I can configure ESS in my sleep, but that has a downside: I get sloppy. I go "naaah the defaults are fine... next next next...". And for me it is fine, because this is just a test system and we're blowing this config away again tomorrow, but it would be best if there was a group of enthusiasts who could play with these things themselves :-)

What you have to keep in mind though, is that to run ESS you need a Venus device and/or some cabling. This adds between 2k and 4k after the cost of the inverter and the solar chargers, but it also gets you remote access/control of your installation (via cell phone) and remote diagnostics/charting/data collection, all thrown in for free.

I really wouldn't want it any other way, because there is nothing that is this tinker-friendly and flexible. I'd be very frustrated with a Goodwe or a Solax, I know it in my heart :-)

14 minutes ago, plonkster said:

It would be nice if the ones who were helped can again help others... :-) They know who they are... :-P

We do, and we are going to take this to the top level at Victron. See, we, the ones you know of, have figured out how and what is needed to make Victron easier than a Axpert, to install and configure. We will do the effort, if Victron would consider to make a few menu changes on the VenusGX, RPi and CCGX.

And we are going to start a ESS group here ... I'm slowly coloring in the stick figure picture. ;-)

+-95% of the options are useless to a newbie.
Like I found the place to hide them, and that you need a powered USB hub to extend the USB port on the VenusGX. 
And with the VenusGX, I can use a D-Link WiFi adapter. ;-)
And going to Github, no no no no ... NO!!
You want more than the bare bones menu option setup, the one we are going to put together, speak to a Victron installer, just like with any other inverter out there.
Do NOT bother Victron support unless you have talked to a installer - Note: This rule does NOT apply to the "people who know who they are". :-)

4 minutes ago, The Terrible Triplett said:

And going to Github, no no no no ... NO!!

Oh come on! That's like the coolest place in the world! Well... we'll have to see where it will go now Microsoft has acquired it :-)

How can you call yourself a techie and not like github?

5 minutes ago, The Terrible Triplett said:

+-95% of the options are useless to a newbie.

95% of the options aren't meant for Newbies.

5 minutes ago, The Terrible Triplett said:

few menu changes

You go to github and you log a feature request :-) The Dutch has a very efficient way of telling you what station you can get off at if you're wrong.