Inverters and Batteries

[deondpz]

I want to install a hybrid system. 

Understand that new regulations limit an installation to 4.6kW  - is that true?

Victron is at the high price end and Mercer King on the lower end. What drives the decision to go for the Victron units instead?

Batteries to consider - I  looked at Blue Nova, Freedom Won (LITE) and Pylontech. What are your recommendations , any other options to consider?

Regards

Deon 

[Rclegg]

Hi Deon, 

Which regulations have you read about that limit? I know in CoCT there is a 3.5Kw limit of sorts. 

As far the inverter, it comes down to budget and expectations. The Blue stuff (Victron) is very nice - however out of budget for a lot of people. So, that's generally what drives the decision making process there. I went for the Axpert MKSII 5Kva unit and its been working flawlessly. It might not last as long as the Blue Stuff will, and thus when it does break, I will replace it with the Blue Stuff if budget allows. 

Batteries: 

I went for the Pylontech 3.5kw batteries. A lot of people on these forums use them and recommend them. There are others though as you mentioned; can't comment on them. 

[Stanley]

Regarding the CoCT size limits, this is the latest document which makes it much clearer.

[Louisvdw]

31 minutes ago, deondpz said:

hybrid system

Hybrid does not mean the same anymore. It is used for different things these days. So just to clarify if you say hybrid do you mean it should be able to blend the power from the available solar with the rest coming from the grid? The Victron Multiplus inverters and larger all does this (called PowerAssist), while most Axpert inverters do not (I think the King might, but just make sure)

Those that does not do blended power will switch to grid completely as soon as your load goes over the max the inverter can supply. 

36 minutes ago, deondpz said:

Blue Nova, Freedom Won (LITE) and Pylontech

These batteries all have good communication with the Victron products. Pylontech I know has comms options with Axpert. Not so sure about the other two. Blue Nova and FreedomWon are local manufacturers. Pylontech is from China but do have good support locally.

[Stanley]

For batteries, I can recommend Freedom Won, Solar MD and Pylontech.

Pylontech is nice because it's modular and you can easily add more later.

Solar MD also allows adding more quite easily but they are wall mounted or their own proprietary rack mount form factor (so must use their rack)

Freedom Won is floor standing and look quite pretty, you can also add more but only of the same capacity so if you start big you can't add just a little bit more later.

[___]

1 hour ago, deondpz said:

Victron is at the high price end and Mercer King on the lower end. What drives the decision to go for the Victron units instead?

Quality. The Victron unit has a 5 year warranty and generally last more than 10. It has excellent support from the manufacturer. Firmware updates are available and free. The VRM telemetry site is arguably the best available in the business today. Though the cost appears high, it's actually cheaper than many competitors.

For the Voltronic unit, the warranty is 2 years, they generally last about 5, support from the manufacturer is non-existent (though admittedly the local agents are not too bad), 3rd party telemetry is your only option (aka ICC), and if there is a bug in the firmware... good luck. The only other competition in the same price class is even worse.

Battery wise, I rank them like this, at the risk of angering some people I leave out batteries that might not be available in this country, eg the excellent Discover AES battery.

1. BYD. They are available in the country but I don't often see them used. I assume it's the price. The new Premium battery is excellent. It's a 16s battery and has excellent maximum charge and discharge currents.

2. Pylontech. I put them this high up because of good support, good warranty, they did well in the Ausie battery benchmarks, and it's an honest battery. They tell you upfront that their EOL is at 60% and the discharge rate is C/2. Not as good in this regard as the BYD, but not bad either. Support-wise I would probably put them ahead of BYD even, but I think BYD has a small technical lead on them.

3. FreedomWON. Local maker, looks good, uses an excellent BMS (Orion BMS). Good charge and discharge current levels. Does good voltage control and doesn't need any workarounds in the software (the above two do in some cases).

4. SolarMD. Excellent battery, though somewhat pricey. Not many installers offer it as an option, I suspect because becoming a distributor is not as simple as with the others. I heard through the grapevine you need to register as reseller and it costs a small fee. Good charge and discharge currents (1C).

5. BlueNova. Uses Winston cells, which is excellent but adds some costs. Has their own BMS. Earlier batteries had some issues in that respect, later ones are much better. Battery capacity is determined based on a C/10 discharge rate, which in my opinion is cheating a little, but can be dismissed as "marketing boosting the numbers". It may be more realistic as to how people will really use them in a residential setting, but it also means that when comparing with other batteries (the least of which uses C/2) you are not doing apples for apples. So do keep in mind when you do comparisons.

Edited to add:

6. Revov. Second-life batteries. A bit of a mixed bag, some people report success, and some don't.

7. LithiumBatteriesSA. A bit of a newcomer to the arena, but popular with DIYers. Watch this space, I suspect a new battery might be coming. Generally uses the Daly BMS. Lower end BMSes don't have comms. I'd probably take one of these over a Revov once it stabilises a bit.

Edited September 4, 2020 by plonkster

[JustinSchoeman]

43 minutes ago, plonkster said:

7. LithiumBatteriesSA. A bit of a newcomer to the arena, but popular with DIYers. Watch this space, I suspect a new battery might be coming. Generally uses the Daly BMS. Lower end BMSes don't have comms. I'd probably take one of these over a Revov once it stabilises a bit.

I suspect this is the new battery you suspect to be coming?

https://lithiumbatteriessa.co.za/collections/frontpage/products/lbsa-6kwh-48v-lifepo4-wall-mount-smart-battery-2nd-life?variant=36090380091559

[Rclegg]

1 hour ago, Louisvdw said:

Those that does not do blended power will switch to grid completely as soon as your load goes over the max the inverter can supply. 

Not strictly true for all Axperts. The king will blend with the grid. The unit I have, (Also Axpert) will blend with battery + PV to supply the load. If that isn't enough, then it goes to grid (or if the spike in load is very high, it goes to grid) 

[deondpz]

3 hours ago, plonkster said:

Quality. The Victron unit has a 5 year warranty and generally last more than 10. It has excellent support from the manufacturer. Firmware updates are available and free. The VRM telemetry site is arguably the best available in the business today. Though the cost appears high, it's actually cheaper than many competitors.

For the Voltronic unit, the warranty is 2 years, they generally last about 5, support from the manufacturer is non-existent (though admittedly the local agents are not too bad), 3rd party telemetry is your only option (aka ICC), and if there is a bug in the firmware... good luck. The only other competition in the same price class is even worse.

Battery wise, I rank them like this, at the risk of angering some people I leave out batteries that might not be available in this country, eg the excellent Discover AES battery.

1. BYD. They are available in the country but I don't often see them used. I assume it's the price. The new Premium battery is excellent. It's a 16s battery and has excellent maximum charge and discharge currents.

2. Pylontech. I put them this high up because of good support, good warranty, they did well in the Ausie battery benchmarks, and it's an honest battery. They tell you upfront that their EOL is at 60% and the discharge rate is C/2. Not as good in this regard as the BYD, but not bad either. Support-wise I would probably put them ahead of BYD even, but I think BYD has a small technical lead on them.

3. FreedomWON. Local maker, looks good, uses an excellent BMS (Orion BMS). Good charge and discharge current levels. Does good voltage control and doesn't need any workarounds in the software (the above two do in some cases).

4. SolarMD. Excellent battery, though somewhat pricey. Not many installers offer it as an option, I suspect because becoming a distributor is not as simple as with the others. I heard through the grapevine you need to register as reseller and it costs a small fee. Good charge and discharge currents (1C).

5. BlueNova. Uses Winston cells, which is excellent but adds some costs. Has their own BMS. Earlier batteries had some issues in that respect, later ones are much better. Battery capacity is determined based on a C/10 discharge rate, which in my opinion is cheating a little, but can be dismissed as "marketing boosting the numbers". It may be more realistic as to how people will really use them in a residential setting, but it also means that when comparing with other batteries (the least of which uses C/2) you are not doing apples for apples. So do keep in mind when you do comparisons.

Edited to add:

6. Revov. Second-life batteries. A bit of a mixed bag, some people report success, and some don't.

7. LithiumBatteriesSA. A bit of a newcomer to the arena, but popular with DIYers. Watch this space, I suspect a new battery might be coming. Generally uses the Daly BMS. Lower end BMSes don't have comms. I'd probably take one of these over a Revov once it stabilises a bit.

 

[deondpz]

Thank you very much for this comprehensive reply.

Is the SMA /Sonny boy route perhaps a option instead of going the Victron route. 

I am considering a 10KVA unit.

Regards

Deon 

[___]

2 hours ago, deondpz said:

Is the SMA /Sonny boy route perhaps a option instead of going the Victron route. 

Of course. But SMA is considered even more upmarket (rightfully so) with a price that goes with it

An SMA system ties all the PV on the AC side, using SunnyBoy inverters. They then have a SunnyIsland that charges the battery, and that can create a microgrid for the SunnyBoys to tie with. It's brilliant for building microgrids, but I think it's a bit overkill if it's just for one house.

[Gerlach]

15 hours ago, deondpz said:

Thank you very much for this comprehensive reply.

Is the SMA /Sonny boy route perhaps a option instead of going the Victron route. 

I am considering a 10KVA unit.

Regards

Deon 

If planning to 10kw, then look at the new  design MLT powerstar. There is plans of it be in the CoCT new list. Just need to dubble check with @Stanley

[Gerrie]

23 hours ago, Rclegg said:

The king will blend with the grid.

Does anybody know whether a inverter that blends solar and grid power make that installations a grid tie installation by definition? 

[Tariq]

No, not necessarily true, can be off grid like the Voltronic Axpert King and VM III