JK BMS CAN bus comms now possible for inverters that support Goodwe and Pylontech batteries

[bds70]

No, it integrates with the Victron ecosystem and can for example set the charge parameters on the MPPT.

I was just reviewing some of my questions and your answer got me thinking. The Victron smart solar MPPT parameters can be changed via the Victron connect app & Bluetooth. What extra parameters would I be able to set?

 

[upnorthandpersonal]

You can set the charge voltage and current limit (CVL/CCL/DCL) dynamically so if e.g. temperature gets too hot you can lower the charge current.

 

[Sleeper85]

You can set the charge voltage and current limit (CVL/CCL/DCL) dynamically so if e.g. temperature gets too hot you can lower the charge current.

Regarding temperature and charging current, are there recommended charging values depending on temperature?

I know that at 0°C we no longer charge but what about high temperatures?

 

[upnorthandpersonal]

Regarding temperature and charging current, are there recommended charging values depending on temperature?

I know that at 0°C we no longer charge but what about high temperatures?

Anything over 30C is something to look out for. Anything over 40C will destroy your battery quickly. There is not hard cut-ff (same as for low temperatures by the way, it's not 0C exact - it's a gradient). 25C is the sweet spot, so if your temp is rising, lower the charge current to mitigate this.

 

[Sleeper85]

Anything over 30C is something to look out for. Anything over 40C will destroy your battery quickly. There is not hard cut-ff (same as for low temperatures by the way, it's not 0C exact - it's a gradient). 25C is the sweet spot, so if your temp is rising, lower the charge current to mitigate this.

In your opinion, what would be the maximum number of amps recommended at 30°C and 40°C for 280Ah cells?

The limitation is both charging and discharging when it's hot, right?

 

[shvm]

In your opinion, what would be the maximum number of amps recommended at 30°C and 40°C for 280Ah cells?

The limitation is both charging and discharging when it's hot, right?

I don't think implementing this is necessary for low C-rates DIY solar applications, but here are C-rate recommendations from EVE and CALB.


EVE charging

EVE discharging


CALB charging

 

[Sleeper85]

@eumobong

Why do you stop charging above 45°C ?

According to the table provided by @shvm , there seems to be no problem charging above 45°C.

if (max(id(temperature_sensor_1).state, id(temperature_sensor_2).state) > 45) { //if battery temp is higher than 45 deg C stop charging
  can_mesg[0] = uint16_t((id(charging_voltage).state - ${float_offset}) * 10) & 0xff;
  can_mesg[1] = uint16_t((id(charging_voltage).state - ${float_offset}) * 10) >> 8 & 0xff;
  can_mesg[2] = 0x00;
  can_mesg[3] = 0x00;
}

 

[upnorthandpersonal]

Why do you stop charging above 45°C ?

Look at the cycle life in the datasheet of EVE and others. You destroy cells at those temperatures.

 

[upnorthandpersonal]

In your opinion, what would be the maximum number of amps recommended at 30°C and 40°C for 280Ah cells?

I never charge over 30C or so (about the hottest it ever gets here). I would definitely not charge at all over 35C.

 

[Sleeper85]

Look at the cycle life in the datasheet of EVE and others. You destroy cells at those temperatures.


View attachment 192044

Thank you for pointing this out

 

[Sleeper85]

I never charge over 30C or so (about the hottest it ever gets here). I would definitely not charge at all over 35C.

This will certainly be part of version 1.16.5 while leaving the choice of the maximum temperature to users.

 

[arzaman]

Hy Guys
Just a simple reference connection schema for wireless and wired option using M5stack Atom and CAN base





and here my "wireless implementation" with Deye and 16xLifePo4 DIY pack with JK BMS




test will continue !

br
Davide

 

[Sleeper85]

V1.16.4 on GitHub

• Improved Charging Logic for ESP32 startup/reboot and Float charge (the voltage decreases slowly)
• Add CAN ID 0x356 bytes [06:07] cycles for Sofar
• Change switch name in order to be able to differentiate between the BMS switches and those of the CAN application

FYI, I had fun flashing the ESP32 in the middle of the absorption phase and the absorption phase continued after the reboot

 

[Sleeper85]

Just a simple reference connection schema for wireless and wired option using M5stack Atom and CAN base

Thank you very much for all these schemas, I will add them to the GitHub.

Could the Bluetooth version work with Atom Lite?
Or is it only for Atom S3?

 

[arzaman]

Thank you very much for all these schemas, I will add them to the GitHub.

Could the Bluetooth version work with Atom Lite?
Or is it only for Atom S3?

Sure more than happy to contribute !

I will compile the BT version also on the Atom Lite version ESP32 Pico and let you know

Davide


PS S3 version seems quite stable

 

[ChrisG]

Thank you very much for all these schemas, I will add them to the GitHub.

Could the Bluetooth version work with Atom Lite?
Or is it only for Atom S3?

I can confirm wired and Bluetooth is working with this stack, although the human readable time resets at approximately 1hr 45 min.

 

[Sleeper85]

I can confirm wired and Bluetooth is working with this stack, although the human readable time resets at approximately 1hr 45 min.

The reboot after 1h45 is not very good, fortunately the new version 1.16.4 will prevent you from having charging problems.

Do you have a good WiFi connection?
What is the quality of the signal from the ESP?

WiFi Component

Instructions for setting up the WiFi configuration for your ESP node in ESPHome.

esphome.io

reboot_timeout (Optional, Time): The amount of time to wait before rebooting when noWiFi connection exists. Can be disabled by setting this to 0s, but note that the low level IP stack currentlyseems to have issues with WiFi where a full reboot is required to get the interface back working. Defaults to 15min.

 

[ChrisG]

The reboot after 1h45 is not very good, fortunately the new version 1.16.4 will prevent you from having charging problems.

Do you have a good WiFi connection?
What is the quality of the signal from the ESP?

WiFi Component

Instructions for setting up the WiFi configuration for your ESP node in ESPHome.

esphome.io

looks like I need to add a sensor for wifi, but it's about 10ft away from a wired Eero access point. No other devices ever had a problem and when I used this as wired to the JK, it never had a reboot or disconnect.

 

[Sleeper85]

looks like I need to add a sensor for wifi, but it's about 10ft away from a wired Eero access point. No other devices ever had a problem and when I used this as wired to the JK, it never had a reboot or disconnect.

Ok so it's the Bluetooth version which is not stable with Atom Lite.
@arzaman will test the BLE version on Atom Lite.
Wait and see

 

[eumobong]

I never charge over 30C or so (about the hottest it ever gets here). I would definitely not charge at all over 35C.

Cc @Sleeper85 I have not reached 40C before. This is the hottest season and the highest recorded by my jkbms sensor was 37C charging at 70A for close to 2hrs (280k eve battery). Average battery temp is 32-34V