So finally we over the line...The JBD is communicating with the Sunsynk & the Akcome Bi facial panels seem the real deal. A quite overcast sky & at 3pm a peak of 10kW. Very impressive results. 

Looking good, and I like the new look "Freedom Won" battery styling. 😂😂

I had the opportunity to develop a BMS communications gateway for @Steve87 . For this purpose he delivered a 5KW Sunsynk and the latest generation JBD BMS module to me , which made my life an order of magnitude easier .  Steve's roadmap for this gateway (protocol converter) is clear , he wants DIY LFP cell builds and other batteries to become first class citizens as far as Deye / SS inverters are concerned .

BMS communication for Deye / SS is not actually optional . The machines rely on SOC for its work mode timers etc (although voltage metrics are supported , its pretty useless). But also the SS is much more sensitive to BMS protection when a cell goes over limit etc. In short it doesn't like interruptions in battery feed , much less so than my beloved MAX7.2 will tolerate .

The design philosophy of the product has been also inspired by similar work carried out by @JustinSchoeman . His  charge de-rating algorithm on his public GIT is very comprehensive. I have only really implemented a subset of this currently , and will revisit his adaptive de-rating algorithm during the winter months . I must also credit Justin for inspiring me to go a soft (bit-banged) implementation of canbus for Pi Pico . This has been very exciting and I have subsequently came up with a canbus controller that is compliant and very very cost effective . To the tune that adding another can port merely includes a small can transceiver.

So the function for the gateway is mission critical , and that has influenced my design somewhat . Low cost Embedded Linux devices are not welcome , and its actually overkill , it draws too much power and SD-cards are most unwelcome. I had to select an embedded controller that's also economical on power requirements. I decided to take the Raspberry PI PIC microcontroller on ,  and I am so far not disappointed.  I have employed an industrial isolated , regulated power supply , which also serves to provide isolated canbus and RS485 communications , something that's very important when your product lives inside a battery enclosure environment. Although no particular considerations have been given to intrinsic safety (mining specs) , I have selected quality MORNSUN industrial isolated  power supply that has a wide input range of 36 - 75VDC . AC supply is NOT an option , we don't want the grid to enter the territory of Battery enclosures. !!!!   Another aspect of intrinsic safety is that my controller draws less than 50mA at 5V , so we can current limit to a good low value. EDIT : oh , and very  important , the module is protected from incorrect battery input polarity. 

Currently I have one RS485 port and one CAN 2.0 Port , although my PCB design for Steve will include two of each.  This will allow us to also support Voltronics inverters which has predominantly RS485  support and very limited canbus support .

Also part of the design is approach a notion of zero configuration. Ideally the product must be flashed with the wanted protocols , but the settings etc must be obtained from the host BMS , which in turn is well equipped with smart phone bluetooth apps for tuning the BMS. I have succeeded in this regard , expect for one metric : the maximum allowed charging voltage !!!!!!  Currently I have hardcoded this on ad-hoc basis , in the future I will have to devise methodology to entertain user programmable setting for this.

One more thing . If there is something that irritates me to no end , its the lack of simple diagnostics to inform the user  whether the product is healthy or not .  Solar products are notoriously famous for this. We have implemented a single LED indication for this purpose . The LED flashes 1 to 4 pulses  periodically every 4 seconds. 1 pulse indication means  product is working but no communication , 2 pulse means JBD RS485 comms working but not canbus, 3 pulses means canbus working but not RS485, and 4 pulses means that both RS485 and canbus are working. It doesn't really get easier than that.

 

below is an image of the first prototype . The industrial power module is the black one , the size of matchbox. The 8pin canbus chip transceiver is the only evidence of canbus , the rest is under the pico's bonnet!  To aid intrinsic safety I have introduced an inductor and fuse on the battery supply input . The inductor limits the excess inrush current to the filter capacitor onboard .

 

If you are interested in  bms protocol converters  contact  Steve87.

 

EDIT : I have also introduced a WS2812 RGB led string driver  in order to support 12 , 16 or 24 led string  halo rings for SOC display etc. However I currently faced with the miserable dilemma of supporting such ring in a good looking enclosure . It looks so unprofessional when you have  half-baked mounting  support. Steve has already invested in 3D printer , but it has caught up with us in terms of time , but hopefully in the not so distant future we will render a housing for such halo ring.

Edited April 15, 20233 yr by BritishRacingGreen

17 minutes ago, TimCam said:

Looking good, and I like the new look "Freedom Won" battery styling.

Really was not my 1st choice at all but to keep costs down we recycled a box that otherwise was bound for the rubbish bin.

10 minutes ago, BritishRacingGreen said:

I had the opportunity to develop a BMS communications gateway for @Steve87 . For this purpose he delivered a 5KW Sunsynk and the latest generation JBD BMS module to me , which made my life an order of magnitude easier .  Steve's roadmap for this gateway (protocol converter) is clear , he wants DIY LFP cell builds and other batteries to become first class citizens as far as Deye / SS inverters are concerned .

BMS communication for Deye / SS is not actually optional . The machines rely on SOC for its work mode timers etc (although voltage metrics are supported , its pretty useless). But also the SS is much more sensitive to BMS protection when a cell goes over limit etc. In short it doesn't like interruptions in battery feed , much less so than my beloved MAX7.2 will tolerate .

The design philosophy of the product has been also inspired by similar work carried out by @JustinSchoeman . His  charge de-rating algorithm on his public GIT is very comprehensive. I have only really implemented a subset of this currently , and will revisit his adaptive de-rating algorithm during the winter months . I must also credit Justin for inspiring me to go a soft (bit-banged) implementation of canbus for Pi Pico . This has been very exciting and I have subsequently came up with a canbus controller that is compliant and very very cost effective . To the tune that adding another can port merely includes a small can transceiver.

So the function for the gateway is mission critical , and that has influenced my design somewhat . Low cost Embedded Linux devices are not welcome , and its actually overkill , it draws too much power and SD-cards are most unwelcome. I had to select an embedded controller that's also economical on power requirements. I decided to take the Raspberry PI PIC microcontroller on ,  and I am so far not disappointed.  I have employed an industrial isolated , regulated power supply , which also serves to provide isolated canbus and RS485 communications , something that's very important when your product lives inside a battery enclosure environment. Although no particular considerations have been given to intrinsic safety (mining specs) , I have selected quality MORNSUN industrial isolated  power supply that has a wide input range of 36 - 75VDC . AC supply is NOT an option , we don't want the grid to enter the territory of Battery enclosures. !!!!   Another aspect of intrinsic safety is that my controller draws less than 50mA at 5V , so we can current limit to a good low value. 

Currently I have one RS485 port and one CAN 2.0 Port , although my PCB design for Steve will include two of each.  This will allow us to also support Voltronics inverters which has predominantly RS485  support and very limited canbus support .

Also part of the design is approach a notion of zero configuration. Ideally the product must be flashed with the wanted protocols , but the settings etc must be obtained from the host BMS , which in turn is well equipped with smart phone bluetooth apps for tuning the BMS. I have succeeded in this regard , expect for one metric : the maximum allowed charging voltage !!!!!!  Currently I have hardcoded this on ad-hoc basis , in the future I will have to devise methodology to entertain user programmable setting for this.

One more thing . If there is something that irritates me to no end , its the lack of simple diagnostics to inform the user  whether the product is healthy or not .  Solar products are notoriously famous for this. We have implemented a single LED indication for this purpose . The LED flashes 1 to 4 pulses  periodically every 4 seconds. 1 pulse indication means  product is working but no communication , 2 pulse means JBD RS485 comms working but not canbus, 3 pulses means canbus working but not RS485, and 4 pulses means that both RS485 and canbus are working. It doesn't really get easier than that.

 

below is an image of the first prototype . The industrial power module is the black one , the size of matchbox. The 8pin canbus chip transceiver is the only evidence of canbus , the rest is under the pico's bonnet!  To aid intrinsic safety I have introduced an inductor and fuse on the battery supply input . The inductor limits the excess inrush current to the filter capacitor onboard .

 

If you are interested in  bms protocol converters  contact  Steve87.

A note to @JustinSchoeman : We have discussed 5V IO tolerance for 3.3v system on another thread a while ago. I have subsequently copied from the horses mouth , Eben Upton from raspberry PI , that the Pico IO's  is in fact 5V tolerant , but he cannot state it in the data sheets because the de-facto standard is that a 3v3 system must be 5.5v tolerant , which the pico is not. This is great news as I have selected 5V powered canbus and RS485 transceivers , and it operates without level shifting.

On 2023/04/05 at 10:03 PM, Bl4d3 said:

Got more info on the incorporation of the loadshedding schedule? I've got the latest version of Solar Assistant installed and havent seen such a feature.

And lastly, have you run into any issues of interference with the battery comms cable when the batteries are charging at high currents? Ours drops connectivity often only during high current. Have tried rerouting the cable but doesnt seem to have solved the problem.

https://solar-assistant.io/help/grid/eskom

On 2023/04/05 at 10:03 PM, Bl4d3 said:

Got more info on the incorporation of the loadshedding schedule? I've got the latest version of Solar Assistant installed and havent seen such a feature.

And lastly, have you run into any issues of interference with the battery comms cable when the batteries are charging at high currents? Ours drops connectivity often only during high current. Have tried rerouting the cable but doesnt seem to have solved the problem.

Both can-bus and RS485  comms are highly resilient and immune to common mode noise , so that is a bit of a surprise to me . The only thing that may influence this is the lack of terminating resistors of 120R at the two end of the cable. In saying that , those resistors are typically standard on the controller printed circuit boards.  If you really suspect noise , you can change your cable to STP  or FTP  shielded or foil shielded type and  earth one end of the shield (not both).

On 2023/04/15 at 6:12 PM, BritishRacingGreen said:

However I currently faced with the miserable dilemma of supporting such ring in a good looking enclosure . It looks so unprofessional when you have  half-baked mounting  support.

Ha ha, I know the feeling, even 3D printed enclosures are not the best looking but are OK for a small run of beta testers. Injection molding etc, is extremely expensive.😲

Looking forward to the finished product. Maybe fiddle with some DIY lithium batteries in the future.👍

15 hours ago, BritishRacingGreen said:

Both can-bus and RS485  comms are highly resilient and immune to common mode noise , so that is a bit of a surprise to me . The only thing that may influence this is the lack of terminating resistors of 120R at the two end of the cable. In saying that , those resistors are typically standard on the controller printed circuit boards.  If you really suspect noise , you can change your cable to STP  or FTP  shielded or foil shielded type and  earth one end of the shield (not both).

I may just doo that. Did some testing over the weekend, anything above 4.5kw running through the battery cables causes the battery comms to stop working. The comms cable is running directly along side the negative cable (loosely next to it) as that is the side where the Pi is situated.

Just now, Bl4d3 said:

I may just doo that. Did some testing over the weekend, anything above 4.5kw running through the battery cables causes the battery comms to stop working. The comms cable is running directly along side the negative cable (loosely next to it) as that is the side where the Pi is situated.

I had some issues with unshielded lan cable, comms would cut off for a few seconds a few times a day, using shielded cable sorted it out

On 2023/04/15 at 6:12 PM, BritishRacingGreen said:

I had the opportunity to develop a BMS communications gateway for @Steve87 . For this purpose he delivered a 5KW Sunsynk and the latest generation JBD BMS module to me , which made my life an order of magnitude easier .  Steve's roadmap for this gateway (protocol converter) is clear , he wants DIY LFP cell builds and other batteries to become first class citizens as far as Deye / SS inverters are concerned .

BMS communication for Deye / SS is not actually optional . The machines rely on SOC for its work mode timers etc (although voltage metrics are supported , its pretty useless). But also the SS is much more sensitive to BMS protection when a cell goes over limit etc. In short it doesn't like interruptions in battery feed , much less so than my beloved MAX7.2 will tolerate .

The design philosophy of the product has been also inspired by similar work carried out by @JustinSchoeman . His  charge de-rating algorithm on his public GIT is very comprehensive. I have only really implemented a subset of this currently , and will revisit his adaptive de-rating algorithm during the winter months . I must also credit Justin for inspiring me to go a soft (bit-banged) implementation of canbus for Pi Pico . This has been very exciting and I have subsequently came up with a canbus controller that is compliant and very very cost effective . To the tune that adding another can port merely includes a small can transceiver.

So the function for the gateway is mission critical , and that has influenced my design somewhat . Low cost Embedded Linux devices are not welcome , and its actually overkill , it draws too much power and SD-cards are most unwelcome. I had to select an embedded controller that's also economical on power requirements. I decided to take the Raspberry PI PIC microcontroller on ,  and I am so far not disappointed.  I have employed an industrial isolated , regulated power supply , which also serves to provide isolated canbus and RS485 communications , something that's very important when your product lives inside a battery enclosure environment. Although no particular considerations have been given to intrinsic safety (mining specs) , I have selected quality MORNSUN industrial isolated  power supply that has a wide input range of 36 - 75VDC . AC supply is NOT an option , we don't want the grid to enter the territory of Battery enclosures. !!!!   Another aspect of intrinsic safety is that my controller draws less than 50mA at 5V , so we can current limit to a good low value. EDIT : oh , and very  important , the module is protected from incorrect battery input polarity. 

Currently I have one RS485 port and one CAN 2.0 Port , although my PCB design for Steve will include two of each.  This will allow us to also support Voltronics inverters which has predominantly RS485  support and very limited canbus support .

Also part of the design is approach a notion of zero configuration. Ideally the product must be flashed with the wanted protocols , but the settings etc must be obtained from the host BMS , which in turn is well equipped with smart phone bluetooth apps for tuning the BMS. I have succeeded in this regard , expect for one metric : the maximum allowed charging voltage !!!!!!  Currently I have hardcoded this on ad-hoc basis , in the future I will have to devise methodology to entertain user programmable setting for this.

One more thing . If there is something that irritates me to no end , its the lack of simple diagnostics to inform the user  whether the product is healthy or not .  Solar products are notoriously famous for this. We have implemented a single LED indication for this purpose . The LED flashes 1 to 4 pulses  periodically every 4 seconds. 1 pulse indication means  product is working but no communication , 2 pulse means JBD RS485 comms working but not canbus, 3 pulses means canbus working but not RS485, and 4 pulses means that both RS485 and canbus are working. It doesn't really get easier than that.

 

below is an image of the first prototype . The industrial power module is the black one , the size of matchbox. The 8pin canbus chip transceiver is the only evidence of canbus , the rest is under the pico's bonnet!  To aid intrinsic safety I have introduced an inductor and fuse on the battery supply input . The inductor limits the excess inrush current to the filter capacitor onboard .

 

If you are interested in  bms protocol converters  contact  Steve87.

 

EDIT : I have also introduced a WS2812 RGB led string driver  in order to support 12 , 16 or 24 led string  halo rings for SOC display etc. However I currently faced with the miserable dilemma of supporting such ring in a good looking enclosure . It looks so unprofessional when you have  half-baked mounting  support. Steve has already invested in 3D printer , but it has caught up with us in terms of time , but hopefully in the not so distant future we will render a housing for such halo ring.

I designed and certified (when SABS was still a functional entity) an intrinsically safe PSU for the coal mines some decades back.
If I recall it was a 14V, 400mA design. It started out as a 15V design, but would fail the spark chamber test at 15V vs 14V. (That was a nerve racking test.)

One of the requirements for fuses in IS environments is that they had to be a sand filled to quench the arc during fusing.

On 2023/04/03 at 7:10 PM, Steve87 said:

Hi guys, no I actually got permission rights & all of my Solar Assistant sites have my company logo displayed & its with Permission from Pierre the main owner & developer. 

I run & support numerous sites & his product is really a product that in my opinion is superior to many. He started off small & his product is reaching far places globally. I am very happy to support such a local grown product. 

I think especially in the US his product will gain a lot of traction. Having looked at the Solar man and Sunsynk logger, they are light years behind, only good for notifications, nothing else.  His latest feature now incorporates the Loadshedding schedules for your location. 

I have the latest official release of the software - where do we get the loadshedding shchedules? Is that perhaps in the next BETA?

 

I followed th elink shared in an earlier post - I dont' have that option for Grid in the advanced settings?

Edited April 17, 20233 yr by Douw G. Gerber

1 hour ago, Power Me said:

I designed and certified (when SABS was still a functional entity) an intrinsically safe PSU for the coal mines some decades back.
If I recall it was a 14V, 400mA design. It started out as a 15V design, but would fail the spark chamber test at 15V vs 14V. (That was a nerve racking test.)

One of the requirements for fuses in IS environments is that they had to be a sand filled to quench the arc during fusing.

Now you mention it , I actually never gave thought as to why some type of fuse has sand in it , makes sense.

That psu design must have been some R&D for intrinsic safety. I  selected an isolated supply with 3kV barrier. One big design consideration was having this barrier between the battery and my interfaces. I have affected some flashovers when using non-isolated  , and even 50VDC can produce some nasty flash.  

Edited April 17, 20233 yr by BritishRacingGreen

@BritishRacingGreen @Steve87

Just and update we have successfully built the JBD gateway communication between JBD and Sunsynk 8Kw @BritishRacingGreen thanks for all your assistance and expertise on this build much appreciated.