1 hour ago, jgdt said:

"Battery temp1" through to "Battery temp4" actually refer to

Guessing that there are 4 cell groups (with 4 cells each for 16S), so one temp reading per cell group?

Edited March 8, 20233 yr by jgdt

1 hour ago, jgdt said:

Do you perhaps know what "Battery temp1" through to "Battery temp4" actually refer to?

Those are the sensors from 4 of the actual cells, I don't remember exactly which 4 though.

50 minutes ago, Antonio de Sa said:

I can see is the ambient temperature going up when SOC is at 100% and the BMS starts to equalize the cells.

Makes sense, I would also think the higher the amps used to charge; the hotter they will get. I don't have an image from that same day when they reached 100%, but I have one from another day where they just reached 100% and finished balancing and there is still 6-7 deg difference between ambient and the cells. Your image also has 5 deg difference, so people don't need to worry that the cells are getting as hot as the ambient temp in the room, even when charging.

22 minutes ago, jumper said:

Makes sense, I would also think the higher the amps used to charge; the hotter they will get. I don't have an image from that same day when they reached 100%, but I have one from another day where they just reached 100% and finished balancing and there is still 6-7 deg difference between ambient and the cells. Your image also has 5 deg difference, so people don't need to worry that the cells are getting as hot as the ambient temp in the room, even when charging.

@jumper   I would also think the higher the amps used to charge; the hotter they will get. You are 100% correct, I've done lots of experiments and came to that conclusion.  I came to realize that to get my cells not going over 29/30 degrees the best in my case is to charge at 25 Amps, The higher the charging current the higher the cell temps. Just one thing, what Seplos describes as ambient temperature, it's not the actual temperature in the room. it's actually the BMS dissipating heat while equalizing the cells.

17 hours ago, jumper said:

FYI from my observation, the actual cell temps are usually 5-7 degrees cooler than the ambient temp, as reported by the BMS. Even on a nice toasty day with 35C ambient, the cells are sitting below 29C:

The "ambient temperature" of the Seplos is not the temperature of the room but the temperature inside the case of the batteries. That sensor is generally installed on the PCB of the BMS, near the MOSFET, thus the high temperature at the end of the charging cycle ...

That sensor generally reach +35° on my batteries (Rosen with Seplos) at the end of the charging cycle when the room is at 25°.

@zivva that is exactly what I see when my battery reaches 100% Soc. see dashboard, 

11 minutes ago, zivva said:

The "ambient temperature" of the Seplos is not the temperature of the room but the temperature inside the case of the batteries. That sensor is generally installed on the PCB of the BMS, near the MOSFET, thus the high temperature at the end of the charging cycle ...

That sensor generally reach +35° on my batteries (Rosen with Seplos) at the end of the charging cycle when the room is at 25°.

@zivva what type of USB to RS 485 converter do you use? I want to install the seplos Sofware on my laptop.  

Tried various ones, all works as long as they have a FTDI chip ... But I got fed up of the typical converters with the green terminal blocks and tiny screws where RJ45 wires never fit permanently ...

Now I'm using a USB / RJ45 cable made to monitor EPEVER charge controllers (cable CC-USB-RS485-150U), just need to recrimp the RJ45 end to match the Seplos RS485 pins ...

I believe that cable is available pretty much everywhere for a price equivalent or cheaper than the converters ...

Edited March 8, 20233 yr by zivva

Here's the temps from Solar Assistant.

The MOS temperature is the "ambient temperature" when checking with Seplos software ...

Charging @ 100A, temperatures a bit high 😂

17 minutes ago, zivva said:

Tried various ones, all works as long as they have a FTDI chip ... But I got fed up of the typical converters with the green terminal blocks and tiny screws where RJ45 wires never fit permanently ...

Now I'm using a USB / RJ45 cable made to monitor EPEVER charge controllers (cable CC-USB-RS485-150U), just need to recrimp the RJ45 end to match the Seplos RS485 pins ...

Will this cable work? would I have to recrimp the RJ side.

Looks like the one

You have 3 wires on the cable : RS485A, RS485B, ground ... Red, black & yellow. Can't remember exactly what colors do what though 😂 but I still have the EPEVER wiring diagram, just check the RJ45 end to match. No need for the ground ...

Actually found it :

- yellow pin 4, RS485B

- black pin 6, RS485A

- red pin 8, ground

14 hours ago, Antonio de Sa said:

@zivva that is exactly what I see when my battery reaches 100% Soc. see dashboard, 

What software are you using here? Looks cool. Can you please provide details on your battery, comms cables and software being used?

On 2023/03/07 at 10:31 PM, jumper said:

FYI from my observation, the actual cell temps are usually 5-7 degrees cooler than the ambient temp, as reported by the BMS. Even on a nice toasty day with 35C ambient, the cells are sitting below 29C:

Now that I have Battery Monitor comms to my slave battery, thanks to you, I also see the 5 degree difference between cell temp and the ambient temp (battery box inside) reading. Note however that in my case the highest of the 4 cell readings are displayed on the inverter itself as the battery temp, it did not take the higher battery box ambient temp as I was hoping. And it was this temp that worried me in the first place. See screenshot. Garage ambient temp at this time was 26 degrees. So my cells themselves typically gets to +-31 degrees everyday after charging 😞

.

31° is absolutely not an issue but is more or less an expected temperature when charging. You could start to worry above 40° ...

On 2023/03/10 at 11:34 AM, jgdt said:

Note however that in my case the highest of the 4 cell readings are displayed on the inverter itself as the battery temp, it did not take the higher battery box ambient temp as I was hoping.

At least you know what is being reported now and it is accurately measuring the cells. I agree with @zivvaanything up to 40deg will be fine. Shoto does class these batteries in their "High Temperature" range and the temp warnings only start at 50deg, protection at 65deg, so I wouldn't worry about it.