Hello, can anyone help me determine the version Seplos BMS 3.0?

Hello, I want to update the BMS firmware but I can’t determine version 10 or 11. Who knows, help. Thank you.
The photo shows my BMS.

I've the same (200A 16S) and upgraded the firmware a few days ago with the 48200V11.
New firmware is suppose to fix SOC problems. I have not been able to fully test, but sofar all is running without issues.

Hello, same problem here.
Flashed the v0.5 firmware now because there is only one version for the 200A.

I asked seplos already but no answer so far.

Got reply from Seplos "lem <alan@seplos.com>":

"This number can be connected to the battery monitor to check the firmware version. If it starts with 0., it is v10. If it starts with 1., it is v11.
There are no big changes in these two models."

I did the v10 download went from 0.4 to 0.6 on mine for version.
Did I pick the wrong one or did 0.6 just come out?

Schweg2 said:

I did the v10 download went from 0.4 to 0.6 on mine for version.
Did I pick the wrong one or did 0.6 just come out?

Click to expand...

Hello, everything is correct 0.6 firmware is the latest. It was released on January 23, 2024

Anyone know what has changed from 0.4 to 0.6?
What happens if you flash V10 with V11?

KennM said:

Anyone know what has changed from 0.4 to 0.6?
What happens if you flash V10 with V11?

Click to expand...

I was curious myself, I accidentally flashed v11 and then reverted back to the correct v10 update and didn’t notice anything different.

I will start another fresh thread on this, but for the sake of this post there are some serious issues with the Seplos BMS vs 3.0 and SOC, I have the 200amp version 3.0 with active balancer. I noticed on a fully charged pack that in the morning after a discharge my SOC was showing relatively high 40-50% but cell voltages were low and pack voltage was at 50V,I had discharged around 14kWh from the pack acording to the inverter so I knew it was nearly empty, as this info is passed on to the inverter from the BMS the battery stop discharge at 15% didn't happen as it thought there was still 35% remaining, BMS went in to protect mode after another half hour as cell voltage had dropped bellow 2.8v. Contacted seplos and they sent a firmware update that basically did nothing bar change the resolution of the current in and out at the shunt from measuring 5amp to 1amp for inverter standby draw. As a last straw, i purchased a victron smart shunt, fully charged the pack to 3.65v per cell, reset both SOC to 100% on the BMS and the Smart shunt and did a discharge and charge test. As suspected the Seplos is over estimating SOC by huge ammounts.

See my graph bellow of the SOC of the Seplos VS the victron smart shunt. As of 8am this morning the Seplos shows 65% SOC and the victron shows 40% SOC, as they charge up both converge perfectly at 100% then the drift appears to start again on discharge. Both Seplos and Victron show the current via their respective shunts pretty much the same within 100s of mA of each other. both also show the correct Ah discharge over a set period so that is working fine just the SOC calculations is FUBAR.

Hello, Seplos has updated the software for version 3.0. Here's what they write: This V10 and V11 firmware, update to fix algorithm of SOC, to make sure it more precise.

dzhimiga said:

Hello, Seplos has updated the software for version 3.0. Here's what they write: This V10 and V11 firmware, update to fix algorithm of SOC, to make sure it more precise.

Click to expand...

They did issue a "fixed" FW but all this changed was the resolution of the shunt down to 1Amp from 5Amp still same SOC issues.

Hi Shavermcspud I have the same 200amp V3.0 BMSs with the Victron system and had the same experience as you regarding the SoC calculation, I luckily also had a Lynx Shunt which I have been using to manage the SoC accurately, I completed the update on both BMS's yesterday and 100% charged the battery last night and I now have the Lynx shunt and the Seplos BMS SoC tracking consistently. The resolution of the Seplos is still pants as 0.8amps in a two battery system means I miss anything that's 1.6amps and below on either side but it is significantly better than it was prior to the upgrade. My BMS's are now showing FW version 0.7 compared to the 0.5 I was on prior.



THis is the last 7 days side by side of Lynx shunt vs Seplos, scales are different, but today they are tracking correctly but previously the seplos BMS never went much below 60% that is until I got a low voltage alarm and it dropped straight down to 5% SoC, I will continue to monitor but based on this morning I am pleasantly surprised that they are showing the same data.

Richn83 said:

Hi Shavermcspud I have the same 200amp V3.0 BMSs with the Victron system and had the same experience as you regarding the SoC calculation, I luckily also had a Lynx Shunt which I have been using to manage the SoC accurately, I completed the update on both BMS's yesterday and 100% charged the battery last night and I now have the Lynx shunt and the Seplos BMS SoC tracking consistently. The resolution of the Seplos is still pants as 0.8amps in a two battery system means I miss anything that's 1.6amps and below on either side but it is significantly better than it was prior to the upgrade. My BMS's are now showing FW version 0.7 compared to the 0.5 I was on prior.

View attachment 201653

THis is the last 7 days side by side of Lynx shunt vs Seplos, scales are different, but today they are tracking correctly but previously the seplos BMS never went much below 60% that is until I got a low voltage alarm and it dropped straight down to 5% SoC, I will continue to monitor but based on this morning I am pleasantly surprised that they are showing the same data.

Click to expand...

Thanks for that, I have just seen the new version release on March 5th, and updated mine and done exactly as you have, full charge to 3.65v per cell and reset both SOC to 100%, we shall see what happens from here on in. don't see how this Cr*P passes QC

The soc seems to be fixed now after several more days. But agree not great that the product doesn't do something as simple as correct soc calculation.

I had thought that it was a lack of calibration and the low resolution of the BMS compared to the lynx shunt.

Its working fine now, and has been on point ever since, within 0.5% of my Victron shunt in terms of SOC and current in/out

Do you need to download the firmware to a PC to be able to upgrade? I can't seem to download it?

If you connect via bms studio, you have a option on the top right to update the bms firmware.

degmwilliams said:

Do you need to download the firmware to a PC to be able to upgrade? I can't seem to download it?

Click to expand...

Yes, you need to download the firmware from the seplos side and use bms studio (last tab) to upload the firmware.
Read the firmware update instructions! I did not as usual... and the BMS was hanging during the upgrade(I was afraid I destroyed it as it did not react anymore to the power & reset button...).
Anyways, just taking the inverter power away solved the issue and I could flash it the right way