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Axpert MKS 5KVA Inverter - 48V


Johan Brits

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Just now, Mike said:

the unbranded version of the outback is available in S.A as well..... same factory before shipping out

Pray tell, give more information out of pure interest.

 

13 minutes ago, viper_za said:

@The Terrible Triplett Answer me this, why is it that Victron can charge you if you take the cost of the BlueSolar 150/70 charge controller and you want the use the CANUSB interface cable it's more than half the price of the charge controller.

What makes this cable so special?

Can say the same for Ve Direct to USB

Therein me mentioning 4 name brands whom are all kinda to a fashion rather expensive compared to the cheaper Chinese MPPT imports I can get in SA to try and avert the expected nitpicking of one models silly prices for cables, to which I do agree, are ridiculous, but then, I do not know what the others cables cost. :P

Thing is, most Chinese MPPT's that I have seen a while back, did not have connection cables for as we have learned here, the device you connect the cable to, can put the entire connection at risk if someone took a shortcut, as per the laptop USB port Plonster tested the one day. So to protect all and sundry is not that easy if you have international users connecting to any conceivable device that can read data.

And I know Plonskter has said to build a MPPT is not that difficult nor expensive. But to build one that lasts 15 plus years, for sale just about anywhere in the world, is not going to be cheap. The R&D budget is going to be massive to cater for all the oepsies.

 

4 minutes ago, Wetkit said:

Regarding cost, it might be that the other guys have much more complex software algorithms in their MPPT's, making them more efficient???

I think once you have the software, and it is optimal, you tend not to alter it unless there is a huge improvement in re-writing it.

Where the Chinese makes most probably copied and pasted the work on low budget mass produced components to flood the market with forced labour's low priced and nice advertising with no recourse if there is a lash back on false marketing or inferior equipment not preforming as advertised. Zuma Inc will protect them. :D

 

So back the the point: Does anyone know how the MPPT's behave in the Voltronic range versus Outback, Morningstar, Victron ,Stecca?

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Wetkit that won't work. The inverter mppt needs to be made redundant (I'm certain it does nothing anyway). It can't allow 2 lots of pv to flow through while also independently optimizing the 3rd.

They could feed into the batteries but this is less efficient 

Does anyone have better than 10% pv output on rainy day? Pwm gives 10% while mppt should give 30%

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5 minutes ago, Northland said:

Pwm gives 10% while mppt should give 30%

T&C's apply, with fine print, for suppliers to make that claim.

So if someone has a PWM on array one and a MPPT on array two, from same manufacturer, same sized arrays and data read 24/7/365, I would be very impressed if they found such a huge improvement on cloudy days.

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31 minutes ago, Northland said:

Does anyone have better than 10% pv output on rainy day? Pwm gives 10% while mppt should give 30%

Often. Not that we have had many rainy days. I do remember a couple of months back I got 7kWh on a rainy day.Cloud however can be a killer. Recently we dropped to 2kWh for the day but it is not often that one has low production like that. I would say most cloudy days one achieves 60-80% of normal production and 1 in 10 cloudy days is a killer with little or no production.

 

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1 hour ago, viper_za said:

What makes this cable so special?

There's actually two of these cables, the one is a ve-can to ve-bus converter, which links the mppt and the inverter and allows the software inside the inverter (configurable, you load so-called assistants to handle extra hardware) to talk directly the the mppt. This cable is quite expensive, but I sort of understand why.

Then there is the can-usb cable. Now that thing is also ridiculous, but what you should do is try and find alternatives and see if you really get away any cheaper. I couldn't find anything decent in the sub-R2000 block, looking at things like the can232, the usbtin, and then the price goes up when you start looking at things like the actisense nmea2000->usb stuff (cheapest I saw was over 3k). Then add in low volumes, and that this thing has galvanic isolation, and I would say I sort of understand why the genuine cable is so expensive. Please don't get me wrong though, this is an explanation, not necessarily a justification. The price is certainly not ideal, and is the reason why this individual rigged up an arduino-based alternative for himself.

I also have to mention, that some of that price has to do with the fact that yachts are expensive, and if you want your stuff NMEA2000 certified it costs.

My advice, really, is to forget the cable. Buy the CCGX. That comes with a can-bus port, so it's snap snap (RJ45 cable, two terminators both ends) and you're up and running. If you don't want to do that, a cape (aka shield in arduinospeak) for the Beaglebone Black is coming, and that the software already runs on on the BBB.

1 hour ago, Wetkit said:

Have a look at the Micro care MPPT units. Not priced badly.

Agreed. I was a little down on them after my unit failed, but then I had the displeasure of deconstructing a WRND controller... :-) The Microcare isn't up to the standards of the Victrons and the Outbacks, but I know that unit inside out by now and there is really very little to fault, other than perhaps that construction quality isn't quite up there. Simplicity is the ultimate sophistication, it is said, and in that respect this unit really shines.

 

1 hour ago, The Terrible Triplett said:

And I know Plonskter has said to build a MPPT is not that difficult nor expensive. But to build one that lasts 15 plus years, for sale just about anywhere in the world, is not going to be cheap. The R&D budget is going to be massive to cater for all the oepsies.

Woooah! If I said such a thing, I might have been partially drunk :-P I think I also said a few times that I understand WHY they are expensive. Look, it isn't particularly difficult, that much is still true. If you use the simple async buck converter (MOSFET at the top, Scottky diode for the free-wheel side, nice big inductor) then it isn't difficult. Look on youtube, dude called Julian Ilett built his own. But now start looking at the numbers, because you need a FET and Diode that has a low forward resistance, a high reverse breakdown voltage, and a high current rating. Go look for one of those on the electronic sites... I quickly discovered that a DIY unit will set me back over R1000 just in parts... :-)

 

2 hours ago, The Terrible Triplett said:

how is it that Voltronic can make theirs so cheaply?

Cheap labour and volume, most likely. And I'm willing to bet you can't install that thing anywhere near water :-) So a new Axpert is what, about 9k? Which portion of that would be the MPPT? And we know the Microcare, which is pretty decent for the price, is what, about 5.5k, made in lower volumes locally? I can sort of, with a lot of handwaving, see how they do it... :-)

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Come to think of it...

I started working on a ve-direct simulation for the arduino last week. That was because I was mucking around with the vedirect_dbus binary that comes with the CCGX/Venus software, and I didn't have a BMV at the time, so did a quick hack to make the arduino pretend to be a BMV. That worked well, but I quickly noticed that the sofware attempts to read the serial number register, so I implemented enough of the Hex protocol to fake an answer to that... only to cause a double-free() in the upstream code, so clearly I am doing something unexpected... however I'm only mentioning as background history, because...

... I also have code that converts enough of the VE-can stuff to VE-direct for my own software to read it. In other words, I've made a ve-can to ve-direct interface. So if I combine that with some of the simulation code I hacked together last week, this thing could be made fully-functional. So tally up the cost of that, you will need an arduino (cheapest I've seen is R180), you'll need a canbus shield (also around R200, on ebay), probably a case of some sort, some cabling and stuff, so probably cheapest you can do this for, excluding the development cost of the software, and with no galvanic isolation, no certification, warranty voided, would be around R600, and that relies on a lot of open knowledge because some clever individuals hacked enough of NMEA2000 so that I didn't have to pay the 5k permission fee (that comes with an NDA) to see how the protocol works...

... which given how simple it actually turned out to be, is ridiculous!

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47 minutes ago, plonkster said:

... excluding the development cost of the software, and with no galvanic isolation, no certification, warranty voided, ...

...  and that relies on a lot of open knowledge because some clever individuals hacked enough of NMEA2000 ...

Tally those up and give support for free with a free website to host the data for all the users and I think that the R600 is going to be a very tiny molecule in the bucket. ;)

Yet, I cannot argue with the costs if you are a developer having a solid understanding of the basics of what you are doing with connecting DC equipment to a computer / Pi having extensive Linux knowledge, for your own stuff. Then the numbers the rest are being charged seems stupidly expensive. :D

I do not underestimate these hidden costs anymore after my quick attempt to get a Pi working, being a layman, and SolWEB ... let me tell you, the development costs and efforts so far, is not for the faint of heart.

All looks quite simple and easy enough to do, the Pi's, the screens, storing the data and yes we do it quite easily, bar the Pi side and the Victron inverter, thanks to @edmundp Jacques ...  the bloody VICTRON INVERTER .... #%*!*$&# ... it is becoming a very personal matter now. Very personal.

 

Back to the point ... I don't think it is fair to compare costs what a clever developer can do, with the best (read also cheapest) parts online available with a lot of his/her spare time VERSUS building something for the mass market that just works, plug and play, with free software to read the data, that can be sent to a free web database, data accessible from cell or browser 24/7, with all the things that can go wrong, taken care of, or being taken care of.

So IF the cables are more expensive, as is the CCGX, I bet you part of their costs are going to fund continuous development /  improving the Venus software the users want as well as the email support of their products.

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3 hours ago, The Terrible Triplett said:

Pray tell, give more information out of pure interest.

 

Therein me mentioning 4 name brands whom are all kinda to a fashion rather expensive compared to the cheaper Chinese MPPT imports I can get in SA to try and avert the expected nitpicking of one models silly prices for cables, to which I do agree, are ridiculous, but then, I do not know what the others cables cost. :P

Thing is, most Chinese MPPT's that I have seen a while back, did not have connection cables for as we have learned here, the device you connect the cable to, can put the entire connection at risk if someone took a shortcut, as per the laptop USB port Plonster tested the one day. So to protect all and sundry is not that easy if you have international users connecting to any conceivable device that can read data.

And I know Plonskter has said to build a MPPT is not that difficult nor expensive. But to build one that lasts 15 plus years, for sale just about anywhere in the world, is not going to be cheap. The R&D budget is going to be massive to cater for all the oepsies.

 

I think once you have the software, and it is optimal, you tend not to alter it unless there is a huge improvement in re-writing it.

Where the Chinese makes most probably copied and pasted the work on low budget mass produced components to flood the market with forced labour's low priced and nice advertising with no recourse if there is a lash back on false marketing or inferior equipment not preforming as advertised. Zuma Inc will protect them. :D

 

So back the the point: Does anyone know how the MPPT's behave in the Voltronic range versus Outback, Morningstar, Victron ,Stecca?

 

4 hours ago, Mike said:

the unbranded version of the outback is available in S.A as well..... same factory before shipping out

 

1.JPG

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First Victron and now this ... is nothing sacred anymore!!!

Sies, daai naam is sommer lelik - phonetically it can sound funny.

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1 hour ago, The Terrible Triplett said:

First Victron and now this ... is nothing sacred anymore!!!

Sies, daai naam is sommer lelik - phonetically it can sound funny.

It looks like they've ripped off everything under the sun, Victron, Steca, Outback... :-)

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Question: 

Since I have a bunch of 3.2v cells on the way, and my old 12v 1kw model (I don't know what the axpert equivalent is) is in storage with 1kw of 12v panels.... I wonder what the max battery voltage could be. To use lifepo4 would require a firmware update anyway. 
It's pwm model so between 13v and 20v is wasted. So why not make it 5S = 16V? 3.6v charge = 18v. The caps are 35v and the fets 60v.

Why? 
1. Back up inverter 
2. Extra pv input (50A x 18v = 900w) 
3. Can put all night loads (fridge, TV, lights) on this inverter 
4. Can put the 4048 (aka axpert) to sleep saving 35w (well 20w really since the 1kw uses 15w) 
5. Extra inverter capacity 

Possible? 

 

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6 hours ago, Northland said:

Question: 

Since I have a bunch of 3.2v cells on the way, and my old 12v 1kw model (I don't know what the axpert equivalent is) is in storage with 1kw of 12v panels.... I wonder what the max battery voltage could be. To use lifepo4 would require a firmware update anyway. 
It's pwm model so between 13v and 20v is wasted. So why not make it 5S = 16V? 3.6v charge = 18v. The caps are 35v and the fets 60v.

Why? 
1. Back up inverter 
2. Extra pv input (50A x 18v = 900w) 
3. Can put all night loads (fridge, TV, lights) on this inverter 
4. Can put the 4048 (aka axpert) to sleep saving 35w (well 20w really since the 1kw uses 15w) 
5. Extra inverter capacity 

Possible? 

 

sounds fun and well worth a try! Which 3.2V cells are you getting?

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  • 2 months later...

I have the 4 KW Mecer unit installed off-grid on a farm.  The PDF document the supplier sent me ( no manual in the box) lists the max PV as 95 V open circuit but on this forum and some websites it is listed as 145V?

So as a result I connected my four 200-250W panels in series and parallel to 60V(to not exceed the 95V I was given)(70 V measured).  The problem is the Mecer at no time quantifies the PV array at greater than 600W input even in full direct sun.  Why not?  Is the MPPT fully functional? at 145V allowable I can connect the panels all in series and try again but have not yet.

 

comments?

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My rule of thumb is don't exceed 2S of 72 cell (200 W) or 3S of 60 cell (250 W) panels with the 4 kW (5 kVA) models. There are lower limits for many of the lower power models (especially the 12 V and 24 V models).

This is partly to keep the working voltage of the panels under the ELV limit (120 Vdc); this is an Australian requirement that may not apply in South Africa. But the MPPT voltage range (which is difficult to truly pin down) seems to force that limit anyway.

I would certainly not do 4S (all your panels in series), as Voc evenxat room temperature is often over 44 V, more on cild mornings, so that's over 176 V right away. That's very likely to blow up the Solar Charge Controller, and if it didn't is most unlikely to turn on, let alone generate power.

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Good day All.

If feel a bit like a tjop for asking but here goes anyway.....

I have the same inverter , Meccer 5kVa hybrid.  or named VP MKS 5K .

Can i connect the AC output of the inverter directly onto the mains (utility) power with live incoming eskom power?

At the moment i isolate my DB board for eksom powered CB and inverter powered CB. Totally separated. L + N

Can i connect the 2 parts together again and add my AC output from inverter on eskom live?

Ok my helmet and chest protector is on... fire away...

 

 

 

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37 minutes ago, Fritz said:

Good day All.

If feel a bit like a tjop for asking but here goes anyway.....

I have the same inverter , Meccer 5kVa hybrid.  or named VP MKS 5K .

Can i connect the AC output of the inverter directly onto the mains (utility) power with live incoming eskom power?

At the moment i isolate my DB board for eksom powered CB and inverter powered CB. Totally separated. L + N

Can i connect the 2 parts together again and add my AC output from inverter on eskom live?

Ok my helmet and chest protector is on... fire away...

NO, definitely not.  DO NOT CONNECT THE OUTPUT OF THE INVERTER TO MAINS / UTILITY / ESKOM!!!  You will destroy the inverter.

You can connect the MAINS INPUT of the inverter to ESKOM / GRID though.

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huh?! 

"Oh and just for completeness, on those inverters you STILL have to tie the grid to the input, they simply push back on the input. You never connect the output to the grid."

You telling me if the load is low and the batts are charge it puts power back on input AC ?

i thought the input is to supply for bypass mode or to charge batt if selected

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5 minutes ago, Fritz said:

huh?! 

"Oh and just for completeness, on those inverters you STILL have to tie the grid to the input, they simply push back on the input. You never connect the output to the grid."

You telling me if the load is low and the batts are charge it puts power back on input AC ?

i thought the input is to supply for bypass mode or to charge batt if selected

The INPUT connection is actually the GRID connection on these inverters. It is used to supply power to the inverter when the batteries needs to be charged by the grid or if the load is greater than what can be supplied by PV and / or batteries, depending on the configuration. It is also used as an output to the grid (feed in to grid) connection if the load requires less than the available PV and / or battery. The balance is fed to the grid via the INPUT connection, again depending on the configuration. 

The purpose of the OUTPUT connection on the inverter is to supply the LOAD.

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24 minutes ago, Fritz said:

why do they call it hybrid then @plonkster

Sales pitch. (If you don't mind me answering in the mean time.)

To elaborate a bit more...

The definition of a true hybrid inverter is not only about being able to grid tie, but more the fact that it can combine power sources (Grid, PV & battery) to supply the load or feed back to the grid.

The Axpert inverters cannot combine power sources; if the load requires more than the available PV at any point in time, the inverter switches the load to the grid (BYPASS) and use only the grid to supply the load until the available PV increases or the load drops. If the load is e.g. 2KW and the available PV is 1KW, the inverter will switch to BYPASS and draw 2KW from the grid and 0KW from PV.

In the case of a true hybrid inverter, if the load is e.g. 2KW and the available PV is 1KW, 1KW PV and 1KW from the grid will be used to supply the load. Furthermore, if the hybrid inverter is configured to feed back to the grid and the load is e.g. 1KW and the available PV is 2KW, 1KW will be sent to the grid.

Efficiencies & losses ignored

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