geordi
Bunsen Honeydew testing electricity on Beaker
Learning to crawl before I can walk here, so please bear with me a bit. I'm not a newbie to power or solar, but this interconnected communication stuff isn't doing what I expect it to - and as many here have mentioned, the documentation from some of these manufacturers is..... lacking.
The setup:
Grid Boss / FlexBoss 21 installed and operating with (at the moment) 4.5kw of solar attached, and two 15kWh Basen Green (or BasenGreen for the search tool) DIY battery boxes. The system is set up for ZERO export because the power company won't pay doodly for generation, so why bother.
The primary issue right now: Communication between the two BMS units in the boxes with each other and with the FB21. The batteries are installed in parallel with each other (50v system) via 4/0 cable that are equal length between the two boxes, and (not that I think it matters) the cables to the FB21 are opposite - positive is on the bottom box and negative is on the top.
I DID top balance the batteries before building the packs, but I'm not sure that I know what I'm doing all the way with that either. I understand that there is a possibility of the SoC numbers being wrong anyway, at least initially. But I don't know how to see / trigger the balancing function (or do I even need to worry about this?) but the inverter seemed to receive a stop-charging from the boxes last night and was reporting 98% charge but only 53.3v. My math says that's 3.33v per cell, and only slightly over the 3.20 that they came out of the shipping boxes with? I charged them to showing 3.55 after balancing to 3.6v before building.
The two boxes report WILDLY different SoC numbers in use, and often have different current readings displaying. The voltage showing on each box is the same however.
This MAY be my misunderstanding of how the BMS functions and communicates and / or how it was not really programmed right to start with. I spent DAYS trying to get the RS485-USB to work (the BasenGreen supplied adapter and drivers are hot garbage) and finally ended up with an FTDI chip adapter and able to update the firmware on the boxes and program settings the same on each unit based on post #59 from here: https://diysolarforum.com/threads/basen-green-diy-case-48v-v2.87477/page-3
It would seem that the "Upper" software requires the box addresses to be set to 1 and 2 (and apparently the badly-written software masquerades as number zero, even though you can choose number zero in the list. [shakes head in proper programmer].... So I got them programmed individually and then looked to connect them to the FlexBoss21 - and here's where things get confusing to me.
The FB apparently has a dual-mode port, it can do RS485 or CAN. I understand CANbus, it's a party line system. But the BG boxes only have one CANbus port on them - Can't daisy chain that for communication. But the RS485 doesn't seem to communicate with the FlexBoss? There are three RS485 ports on the BasenGreen boxes, labeled A/B/C.... And not documented at all in their literature. So are these sequential? Party line? Does the FlexBoss need an ID address set somehow or is it automatically number 0 and I shouldn't label either box as number 0?
The lack of documentation sucks. I have the batteries set to use Pylon protocol, and the FlexBoss is set for Lithium and type 2 (whatever that means?) but I'm not sure if there's a better / more communicative protocol option.
There's a lot of discussion here that I've been reading through about "open loop" or "closed loop" communications.... Is there a flag somewhere that will tell me which it is communicating with? The Flexboss DOES seem to receive limit commands from the batteries (or at least one of them) about how much current can be sent - yet the (iphone) monitor app shows "one battery in parallel" and the capacity is 50 ah, which is way wrong. The monitor web page doesn't show that information about parallel batteries, but does show when they are charging or discharging and whether that is "BMS Allowed" or not.
Can the batteries hurt themselves with at least this level of communication? One of the packs was reporting zero percent SoC while the other was saying 60%, and the power readings (from the LCD on the batteries themselves) was 30 amps different but the voltage was .04v apart at 50.36 or 50.40v. I cut it off at 48v b/c on the Flexboss it was still saying 26% SoC at that voltage which didn't seem right to me.
Maybe I'm overthinking this? Please help, and thanks! I have images of most of this, happy to figure out how to post those or fill in any questions other than "why are you doing this if you are a moron over your head?"
I know I'm *almost* over my head.... It's been an adventure up until this lack of documentation / programming difficulty started! Other than these numbers, it DOES do a lot of what I want already, so I figure I'm about 85% of the way to my goal.
The setup:
Grid Boss / FlexBoss 21 installed and operating with (at the moment) 4.5kw of solar attached, and two 15kWh Basen Green (or BasenGreen for the search tool) DIY battery boxes. The system is set up for ZERO export because the power company won't pay doodly for generation, so why bother.
The primary issue right now: Communication between the two BMS units in the boxes with each other and with the FB21. The batteries are installed in parallel with each other (50v system) via 4/0 cable that are equal length between the two boxes, and (not that I think it matters) the cables to the FB21 are opposite - positive is on the bottom box and negative is on the top.
I DID top balance the batteries before building the packs, but I'm not sure that I know what I'm doing all the way with that either. I understand that there is a possibility of the SoC numbers being wrong anyway, at least initially. But I don't know how to see / trigger the balancing function (or do I even need to worry about this?) but the inverter seemed to receive a stop-charging from the boxes last night and was reporting 98% charge but only 53.3v. My math says that's 3.33v per cell, and only slightly over the 3.20 that they came out of the shipping boxes with? I charged them to showing 3.55 after balancing to 3.6v before building.
The two boxes report WILDLY different SoC numbers in use, and often have different current readings displaying. The voltage showing on each box is the same however.
This MAY be my misunderstanding of how the BMS functions and communicates and / or how it was not really programmed right to start with. I spent DAYS trying to get the RS485-USB to work (the BasenGreen supplied adapter and drivers are hot garbage) and finally ended up with an FTDI chip adapter and able to update the firmware on the boxes and program settings the same on each unit based on post #59 from here: https://diysolarforum.com/threads/basen-green-diy-case-48v-v2.87477/page-3
It would seem that the "Upper" software requires the box addresses to be set to 1 and 2 (and apparently the badly-written software masquerades as number zero, even though you can choose number zero in the list. [shakes head in proper programmer].... So I got them programmed individually and then looked to connect them to the FlexBoss21 - and here's where things get confusing to me.
The FB apparently has a dual-mode port, it can do RS485 or CAN. I understand CANbus, it's a party line system. But the BG boxes only have one CANbus port on them - Can't daisy chain that for communication. But the RS485 doesn't seem to communicate with the FlexBoss? There are three RS485 ports on the BasenGreen boxes, labeled A/B/C.... And not documented at all in their literature. So are these sequential? Party line? Does the FlexBoss need an ID address set somehow or is it automatically number 0 and I shouldn't label either box as number 0?
The lack of documentation sucks. I have the batteries set to use Pylon protocol, and the FlexBoss is set for Lithium and type 2 (whatever that means?) but I'm not sure if there's a better / more communicative protocol option.
There's a lot of discussion here that I've been reading through about "open loop" or "closed loop" communications.... Is there a flag somewhere that will tell me which it is communicating with? The Flexboss DOES seem to receive limit commands from the batteries (or at least one of them) about how much current can be sent - yet the (iphone) monitor app shows "one battery in parallel" and the capacity is 50 ah, which is way wrong. The monitor web page doesn't show that information about parallel batteries, but does show when they are charging or discharging and whether that is "BMS Allowed" or not.
Can the batteries hurt themselves with at least this level of communication? One of the packs was reporting zero percent SoC while the other was saying 60%, and the power readings (from the LCD on the batteries themselves) was 30 amps different but the voltage was .04v apart at 50.36 or 50.40v. I cut it off at 48v b/c on the Flexboss it was still saying 26% SoC at that voltage which didn't seem right to me.
Maybe I'm overthinking this? Please help, and thanks! I have images of most of this, happy to figure out how to post those or fill in any questions other than "why are you doing this if you are a moron over your head?"
I know I'm *almost* over my head.... It's been an adventure up until this lack of documentation / programming difficulty started! Other than these numbers, it DOES do a lot of what I want already, so I figure I'm about 85% of the way to my goal.
