Jump to content

Inverter suggestions


JohanB
 Share

Recommended Posts

Hi, 

I have been lurking on here for quite some time, but have finally decided to take the plunge and join the community and the bandwagon. 

I need some advice and shoving in the correct direction.

After countless SLA replacements and unreliability, I have decided to get myself sorted with a proper solution. 

So I have ordered a big boy battery from @Bain Viljoen and am now in the market for a suitable inverter. So my understanding thus far is that Bain's batteries has a suitable BMS for protection but that it does not provide comm's.

I have read other posts where wise men like @plonkster have mentioned the bare minimum a BMS should do and I think it covers that. Then he mentioned nice to haves.

My plan would be to build or buy a bmv7xx type system. Diy would be to use a Microcontroller like the esp32 with a 200A shunt to measure accurate SOC and Draw and then feed this into a Raspberry Pi like Venus Os or icc to replicate the Nice to haves @plonkster spoke about. Not sure how this would work I don't know if I would have to emulate a known battery BMS comms protocol and by using CAN or rs485 feed it into the inverter, or if something like ICC or Venus would be better. Also I would use this to feed into my existing NodeRed network via mqtt for monitoring and controlling of Sonoff's and Grafana.

I also think that a 5Kw 48v system would be sufficient. Later plans include to do gas hob and maybe solar geyser. But for now I need a solid inverter to supply backup loads when there is load shedding or outages. Then as a second phase to add solar and depending on the chosen inverter (hybrid or off-grid) add a second grid-tie inverter. 

So keeping in mind the above mentioned BMS plans, my battery and also adding that I would like to do solar at some stage later but I would like to do it in phases and the fact that I am willing to tinker, what are some recommendations of inverters that would best match my requirements. 

The only constant at this stage is the 6kwh battery from @Bain Viljoen

Thank you if you made it to here. I welcome any and all comments regarding this.

 

Link to comment
Share on other sites

18 minutes ago, JohanB said:

Not sure how this would work I don't know if I would have to emulate a known battery BMS comms protocol and by using CAN

Arduino, with canbus shield, and here is a sketch that pretends to be a can-bus battery...

 

canb.ino

Link to comment
Share on other sites

4 minutes ago, plonkster said:

Arduino, with canbus shield, and here is a sketch that pretends to be a can-bus battery...

 

canb.ino 1.36 kB · 1 download

Awesome thanks,

The Esp32 supports the Arduino IDE so this would be a great starting point. Had a look at the sketch just need to figure out what messages are exchanged between the battery and inverter. Would it just be SOC or would info about individual cells etc also be sent? How complex is such a protocol (minimum features). 

Then obviously if I use a BMV7xx or DIY, would it be better to use the canbus emulation method or just talk to the inverter via venus or icc? Is there benefit to using one method or the other? Is there a standard battery comms protocol and if so any documentation I could refer to, seeing as there is a load of hex in the sketch or Magic Numbers that don't mean much at this stage. 😉 

I would assume the battery speaks it's protocol independently of the inverter and the inverter manufacturers support the battery by implementing the protocol so a generic implementation of said protocol would enable me to communicate with different types of inverters. Might be a project worth pursuing. 🤔

Also this is probably 2 different topics sorry,  but I would also still need inverter recommendations seeing as the battery will have no one to talk to. 😅

Link to comment
Share on other sites

2 hours ago, JohanB said:

Would it just be SOC or would info about individual cells etc also be sent? How complex is such a protocol (minimum features). 

Victron has an extended protocol that can send information about the minimum and maximum cell voltages and temperatures (but not individual cells... since there could be arbitrarily many cells in a battery depending on the series/parallel make-up). The battery doesn't have to listen to any info on the can-bus, it merely needs to send the frames every couple of seconds. Usually you'll send voltage and current frames relatively often (once a second or once every two seconds), and other frames (charge voltage and current, etc) a bit less often, once every ten seconds usually suffices.

The minimum you must implement is 0x351, 0x355, 0x356 and 0x35A. Adding 0x35E and 0x35F is easy, so you must as well throw those two in as well.

What they mean.... look here from page 10 onwards. Protocol is the same. Get the basics going first before messing with the deeper stuff.

Link to comment
Share on other sites

Just now, plonkster said:

The battery doesn't have to listen to any info on the can-bus

Well... let me expand on that. If you want to, but I doubt this will be useful to you, you can listen for 0x305. That is sent by a Victron GX control device and is a keepalive. A battery can use that as a signal that the rest of the system is alive, and shut itself down if not. You can also listen for 0x307, which has the ascii charcters VIC in bytes 4-6, that identifies that your battery is in a Victron system. But again, I really doubt either of these features are usable to you. So you don't have to bother with them.

The CAN-receiver chip will however still receive the messages and you have to either read the messages and discard them (the lazy method which is what my sketch above does), or... you must set the MCP2515 masks so that all traffic is ignored.

Link to comment
Share on other sites

22 minutes ago, plonkster said:

Victron has an extended protocol that can send information about the minimum and maximum cell voltages and temperatures (but not individual cells... since there could be arbitrarily many cells in a battery depending on the series/parallel make-up). The battery doesn't have to listen to any info on the can-bus, it merely needs to send the frames every couple of seconds. Usually you'll send voltage and current frames relatively often (once a second or once every two seconds), and other frames (charge voltage and current, etc) a bit less often, once every ten seconds usually suffices.

The minimum you must implement is 0x351, 0x355, 0x356 and 0x35A. Adding 0x35E and 0x35F is easy, so you must as well throw those two in as well.

What they mean.... look here from page 10 onwards. Protocol is the same. Get the basics going first before messing with the deeper stuff.

Great info thanks.

Sounds like I have some nice weekend reading to do! Now I need to source a MCP2515 breakout. 

Lol, Oh and I need to get an Inverter...

Link to comment
Share on other sites

20 minutes ago, JohanB said:

Lol, Oh and I need to get an Inverter...

The choice of inverter vs comms protocol may go hand in hand. If you go with CAN-bus (which is the industry standard really), that limits your inverter choices and probably excludes the ICC+axpert route (no canbus support on a Raspberry Pi unless you add it yourself).

Link to comment
Share on other sites

8 minutes ago, plonkster said:

probably excludes the ICC+axpert route (no canbus support...

I'm still looking for confirmation, but it seems the latest firmware (perhaps requiring the latest hardware) supports CAN bus to several brands of battery BMS (i.e. the firmware supports more than just Pylontech, though Pylontech seems at this stage to remain RS-485). This is for models with the removable display (Axpert King, Axpert VM III, and a yet to be seen Axpert MKS III aka PIP-5048MGX).

These may still be hard to find in South Africa, or indeed anywhere. But something to keep in mind for the future.

Link to comment
Share on other sites

13 minutes ago, plonkster said:

The choice of inverter vs comms protocol may go hand in hand. If you go with CAN-bus (which is the industry standard really), that limits your inverter choices and probably excludes the ICC+axpert route (no canbus support on a Raspberry Pi unless you add it yourself).

So if I understand it correctly and please correct me if I am wrong. If I manage to implement the protocol I would not need something like ICC, because the inverter would manage the battery better opening up some of the "nice to have" features you spoke off. Or alternatively I could use BMV7xx and ICC?

 

Link to comment
Share on other sites

20 minutes ago, Coulomb said:

I'm still looking for confirmation, but it seems the latest firmware (perhaps requiring the latest hardware) supports CAN bus to several brands of battery BMS (i.e. the firmware supports more than just Pylontech, though Pylontech seems at this stage to remain RS-485). This is for models with the removable display (Axpert King, Axpert VM III, and a yet to be seen Axpert MKS III aka PIP-5048MGX).

These may still be hard to find in South Africa, or indeed anywhere. But something to keep in mind for the future.

I saw this it *looks* like an axpert not sure though... 

https://www.solarpanelenergy.co.za/docs/Synapse 50 48V OffGrid Inverter.pdf

 

It mentions Can-Bus

image.png.e554383b904ea48898459a10b7874efa.png

 

I now saw in the product description: 

Quote

Synapse 5.0K+ Off-Grid 5KW Inverter W/Bluetooth (Voltronic Axpert King 5K).

 

Edited by JohanB
Link to comment
Share on other sites

Following this thread. 

 

I currently have a grid-tied system but moving to a new place where I can't connect Grid-tied.

Ordered the cells from Bain as well. But did not include a BMS. Looking at either a DIY BMS or a smart BMS.

Hybrid Inverter is either the EasySolar 2 48/3000 CX with the mppt. or a Kodak depending if it is for the long run or just to get started.

 

Link to comment
Share on other sites

27 minutes ago, JohanB said:

I saw this it *looks* like an axpert not sure though... 

https://www.solarpanelenergy.co.za/docs/Synapse 50 48V OffGrid Inverter.pdf

No, Synerjis are work-alikes. Though I have to say they have the look of the Axpert King nailed on that one. China is such a weird place.

I wonder if their CAN support is compatible with the Voltronic CAN support. My guess is no.

Link to comment
Share on other sites

1 minute ago, Coulomb said:

No, Synerjis are work-alikes. Though I have to say they have the look of the Axpert King nailed on that one. China is such a weird place.

I wonder if their CAN support is compatible with the Voltronic CAN support. My guess is no.

Exactly what I was wondering about. If they are stating can-bus and they mean rs485...

Link to comment
Share on other sites

6 minutes ago, Luminous said:

Following this thread. 

 

I currently have a grid-tied system but moving to a new place where I can't connect Grid-tied.

Ordered the cells from Bain as well. But did not include a BMS. Looking at either a DIY BMS or a smart BMS.

Hybrid Inverter is either the EasySolar 2 48/3000 CX with the mppt. or a Kodak depending if it is for the long run or just to get started.

 

Yes I ordered a pre-built unit, so it includes a 120A BMS all the necessary protection but no Comms. so My idea would be to build or buy a way to do comms. 

Link to comment
Share on other sites

44 minutes ago, JohanB said:

So if I understand it correctly and please correct me if I am wrong. If I manage to implement the protocol I would not need something like ICC, because the inverter would manage the battery better opening up some of the "nice to have" features you spoke off. Or alternatively I could use BMV7xx and ICC?

It depends entirely. Some inverters have it built in, you snap in the cable and it works. Other makes have an external control unit (eg Victron, you need a GX device to bring it all together). Some use CAN-bus and some use RS485. Some inverters (the true hybrid ones) can use the battery's charge and discharge limits and others cannot. This may also affect the length of the warranty, eg there are batteries that have a shorter warranty if they are used with non-hybrid inverters.

As far as I know ICC doesn't implement any charge and discharge current control, because the inverters it works with cannot do it anyway. The main reason to use it is for better SOC tracking... but if you already have the BMV, there is no added value in that.

Also, I fear we are again going to have the conversation about what a "Hybrid" inverter is. The term Hybrid means to combine two or more features from other devices, so to understand what it means you have to understand what features it is that is being combined. Traditionally a hybrid inverter combined the grid-tied capabilities of a PV-inverter (such as a SMA sunnyboy or a Fronius) with the backup capabilities of an off-grid inverter, so this is what Hybrid used to mean. Unfortunately some people decided to use the same term to describe a device that combines an inverter with a solar charger... which on the face of it does the same thing (it does both PV and backup), but in reality cannot "mix" power like a real hybrid.

25 minutes ago, Luminous said:

Hybrid Inverter is either the EasySolar 2 48/3000 CX with the mppt. or a Kodak depending if it is for the long run or just to get started.

Many of the Kodak's are rebadged Axperts, and I don't consider them real hybrids 🙂

 

Link to comment
Share on other sites

7 hours ago, JohanB said:

Hi, 

I have been lurking on here for quite some time, but have finally decided to take the plunge and join the community and the bandwagon. 

I need some advice and shoving in the correct direction.

After countless SLA replacements and unreliability, I have decided to get myself sorted with a proper solution. 

So I have ordered a big boy battery from @Bain Viljoen and am now in the market for a suitable inverter. So my understanding thus far is that Bain's batteries has a suitable BMS for protection but that it does not provide comm's.

I have read other posts where wise men like @plonkster have mentioned the bare minimum a BMS should do and I think it covers that. Then he mentioned nice to haves.

My plan would be to build or buy a bmv7xx type system. Diy would be to use a Microcontroller like the esp32 with a 200A shunt to measure accurate SOC and Draw and then feed this into a Raspberry Pi like Venus Os or icc to replicate the Nice to haves @plonkster spoke about. Not sure how this would work I don't know if I would have to emulate a known battery BMS comms protocol and by using CAN or rs485 feed it into the inverter, or if something like ICC or Venus would be better. Also I would use this to feed into my existing NodeRed network via mqtt for monitoring and controlling of Sonoff's and Grafana.

I also think that a 5Kw 48v system would be sufficient. Later plans include to do gas hob and maybe solar geyser. But for now I need a solid inverter to supply backup loads when there is load shedding or outages. Then as a second phase to add solar and depending on the chosen inverter (hybrid or off-grid) add a second grid-tie inverter. 

So keeping in mind the above mentioned BMS plans, my battery and also adding that I would like to do solar at some stage later but I would like to do it in phases and the fact that I am willing to tinker, what are some recommendations of inverters that would best match my requirements. 

The only constant at this stage is the 6kwh battery from @Bain Viljoen

Thank you if you made it to here. I welcome any and all comments regarding this.

 

Hi I would recommend the Sunsynk 5.5 Super Hybrid Parity inverter.

7 hours ago, JohanB said:

Hi, 

I have been lurking on here for quite some time, but have finally decided to take the plunge and join the community and the bandwagon. 

I need some advice and shoving in the correct direction.

After countless SLA replacements and unreliability, I have decided to get myself sorted with a proper solution. 

So I have ordered a big boy battery from @Bain Viljoen and am now in the market for a suitable inverter. So my understanding thus far is that Bain's batteries has a suitable BMS for protection but that it does not provide comm's.

I have read other posts where wise men like @plonkster have mentioned the bare minimum a BMS should do and I think it covers that. Then he mentioned nice to haves.

My plan would be to build or buy a bmv7xx type system. Diy would be to use a Microcontroller like the esp32 with a 200A shunt to measure accurate SOC and Draw and then feed this into a Raspberry Pi like Venus Os or icc to replicate the Nice to haves @plonkster spoke about. Not sure how this would work I don't know if I would have to emulate a known battery BMS comms protocol and by using CAN or rs485 feed it into the inverter, or if something like ICC or Venus would be better. Also I would use this to feed into my existing NodeRed network via mqtt for monitoring and controlling of Sonoff's and Grafana.

I also think that a 5Kw 48v system would be sufficient. Later plans include to do gas hob and maybe solar geyser. But for now I need a solid inverter to supply backup loads when there is load shedding or outages. Then as a second phase to add solar and depending on the chosen inverter (hybrid or off-grid) add a second grid-tie inverter. 

So keeping in mind the above mentioned BMS plans, my battery and also adding that I would like to do solar at some stage later but I would like to do it in phases and the fact that I am willing to tinker, what are some recommendations of inverters that would best match my requirements. 

The only constant at this stage is the 6kwh battery from @Bain Viljoen

Thank you if you made it to here. I welcome any and all comments regarding this.

 

 

Link to comment
Share on other sites

1 hour ago, plonkster said:

It depends entirely. Some inverters have it built in, you snap in the cable and it works. Other makes have an external control unit (eg Victron, you need a GX device to bring it all together). Some use CAN-bus and some use RS485. Some inverters (the true hybrid ones) can use the battery's charge and discharge limits and others cannot. This may also affect the length of the warranty, eg there are batteries that have a shorter warranty if they are used with non-hybrid inverters.

As far as I know ICC doesn't implement any charge and discharge current control, because the inverters it works with cannot do it anyway. The main reason to use it is for better SOC tracking... but if you already have the BMV, there is no added value in that.

 

Great explanation makes a whole lot more sense now... So the real answer, as with so many things, is it depends. At this stage I think implementing a compatible can-bus interface seems like a better option...

1 hour ago, plonkster said:

Also, I fear we are again going to have the conversation about what a "Hybrid" inverter is. The term Hybrid means to combine two or more features from other devices, so to understand what it means you have to understand what features it is that is being combined. Traditionally a hybrid inverter combined the grid-tied capabilities of a PV-inverter (such as a SMA sunnyboy or a Fronius) with the backup capabilities of an off-grid inverter, so this is what Hybrid used to mean. Unfortunately some people decided to use the same term to describe a device that combines an inverter with a solar charger... which on the face of it does the same thing (it does both PV and backup), but in reality cannot "mix" power like a real hybrid.

Many of the Kodak's are rebadged Axperts, and I don't consider them real hybrids 🙂

 

By reading here and doing research elsewhere I understand it as you refer to it as a “true hybrid” but it is so confusing as sellers of the equipment and by extension the manufacturers, refer to it as Hybrids. I found a neat trick is to use the City Of Cape town’s list of approved inverters as they list only true hybrids. and grid-tied.

Link to comment
Share on other sites

Feature wise the Sunsync has the same options as the victron. If you ever need to expand they can also be connected in parallel. Ease of setup like the Goodwe, 2 strings in series Voc 5000, A=11, 6500 Wp.  Of panels.

Talks natively to pylontechs and can be configured, like the victron for DIY batteries.

Link to comment
Share on other sites

41 minutes ago, FixAMess said:

Feature wise the Sunsync has the same options as the victron. If you ever need to expand they can also be connected in parallel. Ease of setup like the Goodwe, 2 strings in series Voc 5000, A=11, 6500 Wp.  Of panels.

Talks natively to pylontechs and can be configured, like the victron for DIY batteries.

Does anyone know if the Deye's and SunSynk's are identical, firmware etc...

 

I have been looking at this one:

https://www.solarpanelenergy.co.za/p/958862/5kw-deye-hybrid-inverter

Link to comment
Share on other sites

On 2020/07/25 at 3:15 PM, FixAMess said:

I'm not sure about the firware but the specs look the same.

How does the price compare to Sunsynk?

I could not find a price for a SunSynk, but I found the Deye https://www.solarpanelenergy.co.za/p/958862/5kw-deye-hybrid-inverter it was listed as R 21850.00 (dont know if it is a good price). If someone has a good price on a SunSynk in South Africa let met know, so we can compare.

I would assume a Victron system would be quite a bit more?

Link to comment
Share on other sites

On 2020/07/27 at 7:01 AM, JohanB said:

I could not find a price for a SunSynk, but I found the Deye https://www.solarpanelenergy.co.za/p/958862/5kw-deye-hybrid-inverter it was listed as R 21850.00 (dont know if it is a good price). If someone has a good price on a SunSynk in South Africa let met know, so we can compare.

I would assume a Victron system would be quite a bit more?

You can Contact  Pegasus systems for a 5.5 Sunsynk For R20000.00 ex Vat 

Link to comment
Share on other sites

On 2020/07/27 at 7:01 AM, JohanB said:

I would assume a Victron system would be quite a bit more?

Well, the inverter would be more, but in the context of an entire system, (batteries plus panels) not that much. You also get the modularity (and a lot of other advantages), so future upgrades would likely be cheaper.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...