I have a 8kw Sunsynk 10kw inverter with 18 550w north and west with 3 x Bslbatt 5 kw batteries

My neighbour around the corner installed 2 x 5kw Victron inverters with 16 panels and 4 x Freedom Won batteries.

At the same time during the day, his solar panels deliver 5 to 6 kw whereby mine only hover at 3 to 3.5kw

I have posted about this before but never actually got an answer. Must I just accept that Victron setup is better than Sunsynk???

15 minutes ago, FransSmith said:

At the same time during the day, his solar panels deliver 5 to 6 kw whereby mine only hover at 3 to 3.5kw

Lots of variables here. The first thing to check is the situation of the panels. Are yours facing the same direction, tilted at the same angle etc? Are they same panels? Is there any shade falling on your panels?

Also what are the loads and what is the state of charge (SOC) of the battery?

Earlier this morning, my inverter was pulling 3.5 kW from the panels. But the battery was fully charged by 10:00, and so now the inverter just pulls what it needs to service the loads. At midday, with the heat pump running, it's probably going to be demanding about 2.7 kW from the panels because that's all it will need.

I have a Goodwe inverter. These have four different modes of operation. Usually one uses "general" and then the inverter is constantly balancing PV, grid, battery and loads. If I put it into "off grid" mode then now it doesn't worry about grid and - to finally get to the point - my panels tend to produce a bit more power (or the inverter pulls more from them). So the design and the firmware for the inverter can make a difference to PV performance. But you're talking about 50% relative to your neighbour. I would not expect Sunsynk and Victron to perform identically, but I would also not expect one to give double the performance relative to the other.

You panels are split north and west. This should give you a lower midday peak, but also PV power later into the day.

The main thing here is that your system services the demand from your home with a bit to spare in case there's an early morning outage. That's a better measure than what's coming in from off the roof.

Edited November 12, 2025Nov 12 by Bobster.
Clarity, completeness.

Its not as simple as that - unless you are 100% certain that your panels and neighbours' panels are facing the same direction (to the degree) and are the same spec - its difficult to compare apples to apples. The charge rates / load / inverter efficiencies etc all play into it.

post your app graphs for us to see if your panels are maxed out or if the load is just not there.

10 hours ago, FransSmith said:

At the same time during the day, his solar panels deliver 5 to 6 kw whereby mine only hover at 3 to 3.5kw

I have posted about this before but never actually got an answer. Must I just accept that Victron setup is better than Sunsynk???

No... Unless the total load (power drawn from the panels) are exactly the same. Remember, the PV panels only supply whatever the demand is. Having more panels, all at exactly the optimum angle, etc. will still deliver less power if the demand is smaller for that particular house. Obviously, as @mzezman stated, any difference in panel direction and angle between the two systems will likely result in a difference in PV supply if both loads are the same.

On 2025/11/12 at 10:43 AM, Bobster. said:

Also what are the loads and what is the state of charge (SOC) of the battery?

Earlier this morning, my inverter was pulling 3.5 kW from the panels. But the battery was fully charged by 10:00, and so now the inverter just pulls what it needs to service the loads. At midday, with the heat pump running, it's probably going to be demanding about 2.7 kW from the panels because that's all it will need.

@FransSmith Here's my system today

Note how PV reaches 4kW early on. Then once the battery is charged, PV drops off and just services the loads. Right now it's drawing about 2.5 from the panels because the water heating just switched on. My neighbour's system might be drawing more if we compared them now, but that doesn't mean mine is underperforming, just that we have different loads at different times of day. Also notices how the battery SOC (green line) never goes down as far as 50%. My system only has to replenish a bit less than half of the battery, and on a sunny day it does that quickly.

I could get more out of my system at whatever time of day just by having more stuff on, but I don't see the point.

Edited November 13, 2025Nov 13 by Bobster.
Sppeling

On 2025/11/12 at 10:19 AM, FransSmith said:

Must I just accept that Victron setup is better than Sunsynk???

Short answer is Yes.

3 hours ago, stefan44 said:

Short answer is Yes.

Wow...

@FransSmith , Yes, if you can, post your consumption graph.

Else, just wait till around midday on a sunny day, and then switch on as many heavy loads as you can up to about 8kW, (assuming that the they are either on essentials, or on non-essentials with CT clamp in the right place), then observe you Solar production, it should climb to above 8kW, which your amount of panels should be able to deliver around midday. If not, you need to investigate why, as your system should be capable of providing it.

I agree with @Sidewinder When you put a large, steady AC load on the system (heaters, air fryers, stove plates, geyser, etc.) you force the inverter to take maximum available PV power, because the inverter now has a demand big enough to absorb it. It will show the true capability of the PV + MPPTs, because now the inverter is no longer deciding “I don’t need more PV”.This eliminates 80% of the confusion people have when comparing Sunsynk vs Victron vs Kodak vs anything else.

On 2025/11/13 at 12:18 PM, Bobster. said:

@FransSmith Here's my system today

Note how PV reaches 4kW early on. Then once the battery is charged, PV drops off and just services the loads. Right now it's drawing about 2.5 from the panels because the water heating just switched on. My neighbour's system might be drawing more if we compared them now, but that doesn't mean mine is underperforming, just that we have different loads at different times of day. Also notices how the battery SOC (green line) never goes down as far as 50%. My system only has to replenish a bit less than half of the battery, and on a sunny day it does that quickly.

I could get more out of my system at whatever time of day just by having more stuff on, but I don't see the point.

I think your friends are taking the micky out of you. The panels will only extract what is needed until they max out. I would like to say stay out your neighbours business..... but that's a topic for another day.

Only real comparison you could ever do is connect your DB to his inverter output and check if the behaviour is the same. Your system is performing royally, sit back and enjoy it.

Edited November 24, 2025Nov 24 by Paul.Chari

On 2025/11/12 at 10:19 AM, FransSmith said:

I have a 8kw Sunsynk 10kw inverter with 18 550w north and west with 3 x Bslbatt 5 kw batteries

My neighbour around the corner installed 2 x 5kw Victron inverters with 16 panels and 4 x Freedom Won batteries.

At the same time during the day, his solar panels deliver 5 to 6 kw whereby mine only hover at 3 to 3.5kw

I have posted about this before but never actually got an answer. Must I just accept that Victron setup is better than Sunsynk???

Just taking a chance or eliminating possibilities. Could you give more info about your battery setup, firstly the LiBMS-screen, what values it shows for installed capacity, and the maximum charge rate? Also, under the Battery Settings screen, can you please give the maximum charge rate that is set there?

I'm just thinking from the point of view that the BSLBATT spec sheet indicates a recommended charge rate of 30A (max 50A), and you've got 3 of them, compared to your neighbour that has 4x Freedom Won batteries (charge rate 70A). The difference in charge rates of the battery banks could help explain why your solar production is being limited.

If I may I would like to show the effect of load/SOC to latch onto the reply of @GreenFields

If one had to compare my system with say another one if the time of comparing is 13h30 with low load and battery at 100% the PV ability is low. Yet if one had to look at 13h15 the PV was 100% higher when a high load was on. The same can be seen at 11h50.

This as far as load goes. Then one needs to compare settings and not just what PV watts are installed.

We have to compare apples with apples.

Dark green is PV.

Light green is SOC.

Red is load.

The inverter has nothing to do with your production assuming there is no limitation in the settings. The production difference is most likely caused by the panels, orientation, azimuth, shade... Your 10kw in panels should provide you with at least 6-7kw peak. If you don't get that you have an issue. Also your neighbor has 10 kilowatt inverters and god knows how many more panels. His solar system is 25% in inverterels to mabe even 35% bigger in panels, if it has more of those

1 hour ago, Bursu said:

... Your 10kw in panels should provide you with at least 6-7kw peak. If you don't get that you have an issue. Also your neighbor has 10 kilowatt inverters and god knows how many more panels

@GreenFields mentioned settings. You have mentioned valid points as far as the direction of panels.

Now the BSL 5 kWh batteries are recommended to be used at a 30A charge rate. Thus 3 x30A gives you less than 5 kW. If installed and set up at this level you could never get 6-7 kW from panels for charging if we assume there are no high loads switched on. This is where SOC and load and settings also come into play. There are just too many variables to call the shots without all the information when the comparison is made.

I doubt it 100% it has to do with Sunsynk vs Victron.

On 2025/11/25 at 3:17 PM, Scorp007 said:

I doubt it 100% it has to do with Sunsynk vs Victron.

Before loadshedding, I had a Kaco Powador 5kW hybrid inverter ( long story ). What I didn't have was a battery. Enter full-on loadshedding and I had to make a plan. So, changed to a Sunsynk 5kW to facilitate a battery but made no changes to my existing panels other than splitting them from one string to two.

From my experience, the Sunksynk is getting as much ( read : maximum ) out of the panels as the Kaco did. So 100% it's not a straightforward Sunsynk vs. Victron comparison.

Edited December 3, 2025Dec 3 by hilt_ctn

41 minutes ago, hilt_ctn said:

So 100% it's not a straightforward Sunsynk vs. Victron comparison.

Yes, the OP's question is rather like asking..."My Suzuki 1.2litre petrol gets 5litres per 100km whereas my Mahindra Turbo diesel gets 8 litres per 100km on average. Which is better Suzuki or Mahindra. 😉

If the inverters are set correctly, they can't affect much the solar generation.

Victron has proven reliability with excellent back up service, Sunsynk however has a better "round trip efficiency ".

Both are highly recommended for home installations in SA

On 2025/11/12 at 10:19 AM, FransSmith said:

I have a 8kw Sunsynk 10kw inverter with 18 550w north and west with 3 x Bslbatt 5 kw batteries

My neighbour around the corner installed 2 x 5kw Victron inverters with 16 panels and 4 x Freedom Won batteries.

At the same time during the day, his solar panels deliver 5 to 6 kw whereby mine only hover at 3 to 3.5kw

I have posted about this before but never actually got an answer. Must I just accept that Victron setup is better than Sunsynk???

Victron is not better than Sunsynk. We install both and Victron has more separate components and more to go wrong.
Having said that, Victron is extremely reliable and better suited for corrosive environments such as coastal installations as well as boats and RVs

On 2025/12/31 at 5:51 PM, IanO said:

Victron is not better than Sunsynk. We install both and Victron has more separate components and more to go wrong.
Having said that, Victron is extremely reliable and better suited for corrosive environments such as coastal installations as well as boats and RVs

Out of curiosity, what does the Victron have extra that could go wrong?

Not sure where you are in the world, generally I would think the sun rises, east, travels all the way around southwards then sets in the west. North never gets direct sunlight. This will cause less generation. Unless your roof pitch is less than ten degrees in angle. So with that rule of thumb you'd only want panels east, south, west facing 👍

On 2026/01/15 at 7:22 PM, Lee-I-Am said:

Not sure where you are in the world, generally... North never gets direct sunlight. This will cause less generation.

Well, actually most of us do... and we are NOT lost - most of us ALWAYS get direct sunlight from the north.

What you say is true for half of the World - in the other half, the sun is located to the north... and, in case you have not realised it, this is predominantly a South African forum (although we do have active and very welcome members from over the whole World), and South Africa is located in the southern hemisphere.

So, lesson to learn from this - DON'T assume that just because you live somewhere in the northern hemisphere that everyone else in the world also live there... in fact, don't just assume anything. Why? Because it makes (an) ass (of) you (and) me. 😁

PS - I see this is your first post - WELCOME!

On 2025/11/12 at 10:19 AM, FransSmith said:

I have a 8kw Sunsynk 10kw inverter with 18 550w north and west with 3 x Bslbatt 5 kw batteries

My neighbour around the corner installed 2 x 5kw Victron inverters with 16 panels and 4 x Freedom Won batteries.

At the same time during the day, his solar panels deliver 5 to 6 kw whereby mine only hover at 3 to 3.5kw

I have posted about this before but never actually got an answer. Must I just accept that Victron setup is better than Sunsynk???

Sounds like your neighbour is trying to over compensate for something 😆

On the real though, very difficult comparing an apple with an orange, as the rest of the forum have already commented.

I have 18 x 550w panels, and most days my peak is in the 8kw range.

Once batteries are charged I have a steady load of about 3500w for the pool pump and heat pump + base load.

So there are times when I have no extra load to run to make use of the PV so then the system is only pulling enough for that load of 3500w

Then I have days usually weekends when everyone is home and we have pull every bit of PV available which makes me smile.

I run the batteries down to 50% across all time slots so just to charge the batteries is about 15kw daily.

Would be good to understand your load requirements throughout the day, battery SOC during the time slots etc. all plays a part...

On 2025/11/12 at 10:19 AM, FransSmith said:

I

On 2025/12/31 at 5:51 PM, IanO said:

Victron is not better than Sunsynk. We install both and Victron has more separate components and more to go wrong.

have posted about this before but never actually got an answer. Must I just accept that Victron setup is better than Sunsynk???

On 2025/12/13 at 9:27 PM, giorgos said:

Victron has proven reliability with excellent back up service, Sunsynk however has a better "round trip efficiency ".

6 hours ago, Carl Anthony said:

On the real though, very difficult comparing an apple with an orange, as the rest of the forum have already commented.

Let us try to compare this properly by looking at the 2 inverters Sunsynk and Victron's architecture.

Sunsynk 5 kW Hybrid Behaviour(5kw models as comparison)
Rated Output: 5 kW continuous (≈5 kVA at PF=1) Limited overload capability (very short duration)
What happens at 5 kW load?
When you have PV = 3 kW Battery available = 4 kW capable and your load = 5kw
You would expect PV 3kW + Battery 2kW = 5kW no grid required.
But in reality, with Sunsynk once the inverter AC output reaches its rated ceiling (5 kW):
The inverter does NOT exceed its rating
It does NOT dynamically “overdrive” using battery. If load spikes slightly above internal inverter output capability, it blends in grid power immediately even if battery SOC is high. So what happens in practice if Sunsynk inverter hits 5 kW output ceiling and internal current limit is reached it opens the grid support channel and grid contributes instead of battery surging harder this is because Sunsynk’s hybrid architecture is grid-parallel current limited.
It protects the inverter power stage rather than pushing DC harder.

The Victron MultiPlus-II 5 kVA is a different animal. Rated 5 kVA continuous (~4 kW at PF 0.8) Very strong surge capability (9–10 kW for short duration) But more importantly
It has PowerAssist this is the key difference.
If grid limit set to 5 kW (or lower) load spikes to 6 kW with PV available and Battery available: The MultiPlus uses battery to supplement surges above its nominal rating and reduces grid draw
Only pulls grid if battery cannot support
It is designed as a bi-directional grid-interactive inverter with transformer-based topology and will happily pull 3 kW from battery 2 kW from PV 1 kW from grid
Or:
5 kW from battery/PV alone.even temporarily exceed rating it does NOT immediately fall back to grid simply because it hits nameplate rating.

Sunsynk will often draw grid once inverter output limit is reached.
Victron will pull harder from battery and avoid grid longer. So in real-world high-load scenarios: Victron will typically use less utility power because it allows battery surge support and it doesn’t “give up” to grid at nameplate rating.

I tested the 5kw Sunsynk after installation by increasing the load above 5kw rating and this was the result:

I wouldn’t jump straight to saying Victron is better just based on that.

On paper your system is solid: 18 × 550 W panels is basically a 9.9 kW array.

On a clear day you should definitely be seeing more than 3–3.5 kW around midday. Maybe it's a layout or configuration issue than a brand issue.