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Fact check: Axpert/King vs Victron video


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I recently saw this video on youtube which I don't agree with.  I'm going to post it here so that it can be debated in public.

1) Incorrect: The Axpert inverter can only use battery voltage, not state of charge (SOC).
The battery in the video looks like a PylonTech lithium battery.  Historically Axperts couldn't read the SOC, but this has been added, example:
https://www.enway.co.za/axpert-pylontech-communication-cable-rj45-rs485-bms 

2) The whole premise of the video seems to be that with the Axpert you need a separate grid tie inverter to have a proper setup.  This logic is flawed, the reason is different for the various Axperts:

Axpert king: There is a Solar/Utility/Battery (SUB) mode which means the load is firstly provided by a blend of solar and utility, only if utility is not present it switches to a solar battery blend.  So for Axpert King the logic of (2) above is just outright wrong.
Most other Axperts: It works with a simple mechanism: it runs on Solar/Battery which means if solar isn't enough, the battery is discharged.  Once the battery is lowered to a configured SOC point, the entire load is switched to grid while all solar charges the battery, so no energy is lost.  Once a higher SOC is achieved, the whole load switches back to Solar/Battery.  No need for a separate grid tie inverter.  In his previous video he mentions that a battery could partially solve the problem, when in fact if you don't have a battery the problem doesn't exist at all.  The Axpert MKS II can blend grid and solar if no battery is present, heck it can even run without grid or battery. 

 

My conclusion: Yes Victron is generally better quaility, but this video just spreads misinformation around non-existent limitations of Axpert inverters.  Presumably greenpro is biased towards Victron and is trying to find strong reasons why it's better.  These reasons were there in the past but are disappearing over time as Voltronics improve their products.  This is the story of almost the entire electronics industry: the Chinese products are much cheaper and is slowly but surely closing the gap on quality and features, each year there is less reason to buy the more expensive non-Chinese product.  Think iPhone, Samsung, etc. desperately trying to find reasons why their products are still better than the cheap Chinese phones because they will never be able to halve the price to be able to compete on price.

 

 

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52 minutes ago, pierre. said:

Historically Axperts couldn't read the SOC, but this has been added,

Technically they still can't. Well, they can... they have enough hardware to do Amp-hour counting, but it's just not implemented. In the mean time they made it possible to communicate with the BMS in some models, so now the BMS does the SOC accounting so that the inverter doesn't have to.

For people with lead acid batteries, it is still true that the inverter does not do proper SOC accounting, unless you employ some external solution (Victron BMV and ICC).

55 minutes ago, pierre. said:

with the Axpert you need a separate grid tie inverter to have a proper setup

I think the point he makes is that in order to really seamlessly drive large loads without the inverter switching back to the grid and potentially losing some PV (cause the batteries are full or close to full) is to AC-tie the PV. Of course when you do that, you lose the PV during a grid outage.

This is basically the whole argument for a hybrid inverter... excuse me... a PURE hybrid. Ggnnnh this is like Donald Trump having the twitter handle @realDonaldTrump 🙂

58 minutes ago, pierre. said:

while all solar charges the battery, so no energy is lost

Nope... this is not always the case. In fact, at any SOC above 85%, where the battery is beginning to fill up and the charge current is reducing, the potential for lost energy is there.

The typical situation is this. You have 5kW of PV coming in, and 6kW of load. This exceeds the inverter's capacity, so the inverter switches to the grid. So now the entire 5kW has to go into the batteries, which it will if the battery bank is large and fairly empty, but otherwise the voltage of the battery bank will rise to absorption level within minutes, and the MPPT will start throttling. Now you're in a situation where 5kw of the 6kW of loads could have been offset, but instead 6kW is coming from the grid and the PV is being choked away...

Of course you might argue that for the few times a day this happen, the small amount of lost PV can be ignored, especially in the light of the overall cost of the system, and lots of people accept the limitations for that reason too.

For me, despite my allegiances and all 🙂 I think people can easily be penny wise and pound foolish. With the hybrid inverter, your battery bank can be smaller. You can use a smaller LFP bank because you size it only for backup. Warranties on batteries are often shorter when not used with a Hybrid inverter (eg with Dyness).

And of course... you will buy at least two Axperts for each Multiplus on average. The design life is just shorter. They can be fixed, they can even be improved slightly as our Ausie friends have proven.

But, as I have said before, I really like the Axpert. They turn into future Multiplus sales 🙂

 

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Posted (edited)
3 hours ago, plonkster said:

Nope... this is not always the case. In fact, at any SOC above 85%, where the battery is beginning to fill up and the charge current is reducing, the potential for lost energy is there.

Agreed, but typically you would switch back to battery far below this level, probably 50% or 60% SOC.

3 hours ago, plonkster said:

Technically they still can't. Well, they can... they have enough hardware to do Amp-hour counting, but it's just not implemented. In the mean time they made it possible to communicate with the BMS in some models, so now the BMS does the SOC accounting so that the inverter doesn't have to.

Agreed, but I doubt users care about which component calculates the SOC, just as long as it's there and working.  Theoretically the PylonTech BMS should be the best at calculating their own SOC, so in that regard the "interim" solution might actually perform better.  And for lead acid batteries: I would only install these in a new system if there are severe budget constraints.  I imagine if you are forking out money for a Victron you don't even consider lead acid.

3 hours ago, plonkster said:

The design life is just shorter

What is the design life of an Axpert?

3 hours ago, plonkster said:

The typical situation is this. You have 5kW of PV coming in, and 6kW of load. This exceeds the inverter's capacity, so the inverter switches to the grid.

Valid scenario: but then he should mention it happens when the inverter max load is exceeded, instead of PV generation is exceeded.  Just cut the video short and mention the real advantage of the Victron: the essential and non-essential AC out that hybrids have.  All the other advantages are a consequence of this primary advantage.

Edited by pierre.
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56 minutes ago, pierre. said:

Agreed, but typically you would switch back to battery far below this level, probably 50% or 60% SOC.

It's completely different worlds, that's for sure. I find that due to the cost of batteries, there are many people who run their batteries quite close to the top all of the time. Be that as it may, a totally understand that someone would decide to live with this slight inconvenience rather than pay more.

1 hour ago, pierre. said:

Theoretically the PylonTech BMS should be the best at calculating their own SOC

In the case of Pylontech, indeed, their BMS is not too bad at this. With some other brands I've heard of people installing a BMV to get a better estimate. BlueNova and BYD, for example, don't measure low current levels very well, so at low power levels you get quite a bit of SOC drift. This is however neither here nor there, because the SOC tracking of a Multiplus also isn't perfectly accurate, so this becomes a bit of a long distance urination contest 🙂

1 hour ago, pierre. said:

What is the design life of an Axpert?

It is hard to say. I've speculated on this before, that sometimes you can guess the expected life from the warranty the manufacturer slaps on the product. There will be a maximum return rate they are willing to tolerate, for example a typical figure might be 1%, and the warranty is then chosen such that 99% of the units won't fail within the chosen warranty period. So with a 2 year warranty on most of them, it is rather unlikely that it has a 10-year design life.

But the above model isn't the only warranty model. Some Chinese televisions use another model: You make it cheap enough that you can sell two for the price of one, and the design life might be even less than the warranty. If the unit fails, you swap it. Since not all of them work equally hard or fail, there is still profit in the overall scheme even if a substantial amount of individual models turns into losses or break-evens.

So my thumbsuck is that the Axpert has a 5-year design life. The Victron unit has a 5-year warranty... so the design life has to be more.

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3 hours ago, pierre. said:

Just cut the video short and mention the real advantage of the Victron: the essential and non-essential AC out that hybrids have.

No, not all hybrid have two AC Outs. Goodwe doesn’t, for example. In fact, I only know of Victron that does (but I’m not at all clued up on all inverter specs out there).

There’s numerous advantages of the Victron over the Axpert. One massive one for me is the remote support and management. There’s just so much support. And even if you go Voltronic, your system in total will still be very expensive, so you probably want support, not hours of troubleshooting or painful firmware sourcing...

Basically, a 5kVA Axpert is more comparable with a 3kVA MP II, in my estimation, due to the efficiency gains by being able to use your PV in your entire home, not just on the backup circuit, which will likely be on idle most of the day.

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6 hours ago, plonkster said:

But, as I have said before, I really like the Axpert. They turn into future Multiplus sales 🙂

 

@plonkster I think I will make your day.

My 5kVa Axpert has been running for 3 years, and it is busy serving its purpose well. However after learning about all the different inverters on this forum I will be replacing it with a Victron once it decides to give up the ghost. One soon realizes that there is no substitute for quality and longevity of a product.

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I had the Voltronic standard 5kVA it worked. 

I now have the Victron Multi 2 5000 it is bloody amazing. Like day and night, the out of box functionality and impressive support are definitely a winner. 

No strawberry wot wot and extra software fiddly stuff, Victron just works! 

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13 hours ago, plonkster said:

typical figure might be 1%,

Commenting a bit on my own writing from yesterday.

1% would be absolutely dreadful in some markets. In the automotive segment for example, 1 in 100 units is a public relations nightmare. Car companies have much lower limits here. One example I sometimes use: You remember Toyota slapped a turbo on the 1KZ engine (around 2002, the 3-liter Diesel)? Now that engine has a reputation for having head problems (valve guides, head gaskets), despite the majority of them having no problems at all in their lifetime. But the margins are tight... 🙂

13 hours ago, plonkster said:

sometimes you can guess the expected life from the warranty the manufacturer slaps on the product

The second way is to open one up and look at the components used internally. Even for a layperson, looking at the brand of capacitors they used could be a sign too. If they went with overspec'ed capacitors made by a reputable manufacturer you know an effort was made. That would be makers like Nippon Chemicon, Nichicon, Panasonic, Hitachi perhaps. If you see Jamicon, that still counts as making an effort I think, depending on the specsheet: what is its temperature rating, and how many hours.

Early models of the Axpert had Jamicons, but speced at 63V (too low), with 2000 hours at 105°C. If it works hard about 12 hours out of the day, that works out about 6 months, which also what some people reported in the field (look on youtube for a guy called easily bored engineer). In February 2017 Voltronic switched to a Jianghai capacitor, rated at the same temperature for 4000 hours.

So by looking at just the caps, I expect on average maybe 2 years out of a hard working unit, but if only used as a UPS during an outage it will probably last 5-10 years. Many people however put two in parallel, and they don't work them to full capacity, hence I estimate 5 years for the average setup before one of the two blows.

By that time the Multiplus is just going out of warranty...

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  • 1 month later...
On 2020/08/04 at 5:53 AM, Jaaks said:

I had the Voltronic standard 5kVA it worked. 

I now have the Victron Multi 2 5000 it is bloody amazing. Like day and night, the out of box functionality and impressive support are definitely a winner. 

No strawberry wot wot and extra software fiddly stuff, Victron just works! 

I am thinking that my 5kva Mecer/Axpert is on its last legs. It has lasted a good 3 years this month, but I am now getting a burning smell every time the wife runs the kettle. I opened up the inverter and can't see any melting/damaged components. Even cleaned all the highveld dust out. I recently purchased a Smart Victron 150/45 MPPT external controller for my extra panels and am so damned impressed, that I am now thinking of going all Blue. Besides, I want a device that I can set and forget for the next few years.

My choice is now between a very well priced 2 year old Multi 3kVA and a brand new Multi 5kVa. (This damn rabbit hole)

Oh yes.....I am planning to run the new Victron on a Venus Strawberry PI that @plonksterdeveloped.

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21 minutes ago, Chris Louw said:

@GVC the smell that you get could be a lose connection . I would check al the AC and DC connections off the inverter installation in the erea you get the smell for your safety .

Thanks Chris. I have only given all the wiring a visual inspection.

I will now check properly. Thanks

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2 hours ago, GVC said:

This damn rabbit hole

The blue holes are much cheaper in the long run in my opinion. 

 

2 hours ago, GVC said:

Victron on a Venus Strawberry PI

And you can use my serial battery driver for the Venus if your battery is not normally supported :) 

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35 minutes ago, Dougiedanger said:

Hi GVC, please let me know where you got this particular model? I am also looking to move slowly across to Victron and this size would be perfect for my requirements.

That model's been on the market for close on three years now... 🙂

It's the smallest model in the "new" hardware platform and on a technical level a more advanced product than the entry-level 150/35 (although, now there is a 100/20-48 which is the new entry-level model). I have one in my home system... no complaints. It's like a Toyota Camry, boring but just works.

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2 minutes ago, plonkster said:

That model's been on the market for close on three years now... 🙂

It's the smallest model in the "new" hardware platform and on a technical level a more advanced product than the entry-level 150/35 (although, now there is a 100/20-48 which is the new entry-level model). I have one in my home system... no complaints. It's like a Toyota Camry, boring but just works.

Thanks Plonkster, guys in Zim offered me the 150/35 but that seems just slightly too small for being certain of recharging my battery bank effcetively on a daily basis hence my interest in the 150/45. What are the differences between the 2?

Hadn't come across the 100/20-48 that seems very interesting, who stocks those? Will look fr some info on them as well.

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1 minute ago, Dougiedanger said:

Hadn't come across the 100/20-48 that seems very interesting, who stocks those? Will look fr some info on them as well.

Sorry just read up, I am currently using a 24V system but may in time upgrade to a 48v system so ideally looking for an mppt that can handle both 24v and 48v. Misread your post before and assumed that it had a variable 20-48 amp charging ability. Too quick on the reply before the mind engaged!

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36 minutes ago, Dougiedanger said:

Sorry just read up, I am currently using a 24V system but may in time upgrade to a 48v system so ideally looking for an mppt that can handle both 24v and 48v. Misread your post before and assumed that it had a variable 20-48 amp charging ability. Too quick on the reply before the mind engaged!

Until recently, the 150/35 was the smallest MPPT that could be used in a 48V system. There were smaller MPPTs lower down (100/15, 100/50, etc) but they could only be used up to 24V. The 100/20-48 changed that, it can be used in a 48V system. But you'd probably need two of them in your case 🙂

43 minutes ago, Dougiedanger said:

What are the differences between the 2?

The Smart MPPTs have bluetooth, of course, but internally they have a slightly different architecture too, a different system-on-chip (aka cpu) setup. To the average user that probably doesn't matter at all. But there is also this thing called a current clamp, the newer MPPTs have a hardware clamp, which means that when the maximum current is reached it is held down in hardware. The older MPPTs handled this in software. If there was an overcurrent event (which could happen when you have cloud edge effect or the light level shifted very quickly), these older MPPTs stop charging and ramp up from zero. If you intend on oversizing the array, the newer ones are more suited for that.

The 150/45 is therefore in a different class to the 150/35, but it is of course also reflected in the price 🙂

 

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55 minutes ago, Dougiedanger said:

100/20-48 that seems very interesting

I use these 48V versions. There is a 100/20 that is 12V/24V as well.
They work very well and is a perfect match to 4x 330W panels (2s2p). Mine produce around a constant 970W if the sun is shining around mid day which is very close to their 20A max (20A x 50V = 1000W) Very happy with them.

 

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22 hours ago, plonkster said:

The 150/45 is therefore in a different class to the 150/35, but it is of course also reflected in the price 🙂

I had wondered why there was such a big jump. Back to the budget to work out what I can get and what I need. Thanks for the info

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22 hours ago, Louisvdw said:

I use these 48V versions. There is a 100/20 that is 12V/24V as well.
They work very well and is a perfect match to 4x 330W panels (2s2p). Mine produce around a constant 970W if the sun is shining around mid day which is very close to their 20A max (20A x 50V = 1000W) Very happy with them.

Thanks Louis, I am trying to future proof my purchases, currently have a 24V system, but when my Must inverter dies I would want to upgrade to 48V for more flexibility with chosing lithium batteries.

Also I take about 140ah out of my batteries daily and need an MPPT that can comfortably put that back.

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