Seplos BMS

The battery SOC deos not look right in first picture. Voltage 51.63V is too low for 100% SOC. Have you done full charge/discharge cycle at 0.5C?

These cells will do 2c and higher I think. I think some people are overthinking this saving craic

The Seplos appears to be the only one which can be connected directly to the inverter, by emulating (fooling the inverter into thinking) a connected Pylontech pack.

The AliExpress ones are standalone and the inverter then has to "guess" what the SOC% is constantly.

Got my second pack connected today. Have now 2 batteries in parallel 1x master and 1x slave. The pack do communicate to each other and also balance out to keep the same voltage on both packs. The master is providing total SOC to Solis. My slave pack has not figured out its SOC correctly yet so even though both pack are at same voltage the SOC is different. Hopefully couple cycles will even them out.

On thing that does not work though is software. It can only see salve pack but not master. According to Seplos this is expected as you can have either PC connected or inverter which does not sound right to me. Anyway will keep on testing.

https://m.youtube.com/watch?v=66X1HzDpThg

On this clip you can see the software flicking through the 4 packs this guy has. It that not what you should be seeing?

Has anyone the same problems like I have? Wrote this to Victron Energy in the Victron-Forum:

Everything works fine but before i write a short review here i have a questions, a issue and a problem:

1)

Seplos says they are sending the voltage of every single cell to the inverter but in the Controlpanel i can´t see them!?

I guess this feature need´s programming on your side?

Can you show them into the Panel?

2)

The DVCC-Function "Max. charge-voltage" works perfectly but the function "Max. charge-current" does only act when charging from the Multiplus.

When charging from the MPPT´s this function does nothing.

According to the desccription in the Cerbo-GX manual this function should control the max. charge-current from all inverter/chargers AND all MPPT´s.

Whats wrong here?

3)

The Seplos sends a max. charge current limit (CCL) of 10A when a cell exceeds 3,5V.

In the attached picture you can see that the Systems recognize this but doesn´t react:

CCL is set on 10A but the ESS is charging with full power from the MPPT´s until the BMS cuts of.

Also: Whats wrong here? Is it a software problem or do i only have to adjust a setting?

(I guess Problem 2) and 3) have the same "root"...)

Hi!

My settings in this menu are exactly the same as yours!

What is very strange:

When i set CVL (in DVCC-menu) to 55V or 54V, the "charge voltage" of the MPPT goes down to 55,4V / 54,4V (in MPPT / Networked Operation settings).

(0,4V higher because of cable-voltage-lost i think....wherever i can set these value because i noticed that 0,2V will be more appropriate at my system)

-> So CVL does act in the MPPTs but only CCL does not

I have no idea why and on Victron Forum (Victron community) i don´t get an answer...

my battery is around 100% currently, filled by the MPPT/sushine... here is a screenshot of my parameters while at 100% soc

when the battery gets full, the MPPT continues to generate power - but the inverter sends it to the grid rather than letting it go to the battery.

I haven't been able to see a limit reflected in the MPPT itself similar to the CCL, but controlled by the GX.

A fallback option I am considering for myself is to use basic voltage settings to configure the battery rather than CAN connection. Might be useful while troubleshooting the CAN connection. Longer term I'm hoping to use CAN to control low temp charging properly.

I currently have a manual 60A DVCC limit configured because my baseload went down leaving too much solar excess for my (small) battery. Without that limit, my battery throws alerts relating to over-current.

I'll set it to 20A tomorrow (assuming sunshine) to confirm it works properly - i.e. that the MPPT adjusts it power to baseload + 20A for the battery

test complete

while the sun was shining and charging the battery with 30A+, I set the DVCC limit to 10A. This had no effect - the MPPT kept charging at full speed until the battery approached 100% and then the mppt dialled back the power.

I suspect that setting will affect the Multiplus charging the battery from grid - I can test that tonight if that's helpful.

Then tomorrow after this discharging-night when the sun powers down ☺️

Ok then it´s the same at your system, everthing else would be strange^^

BMS-CCL and "Max. charge current" has no or almost no influence on the System (only when charging from grid with the Multiplus) because it is technically not possible to reduce charge-current when there is PV-power comming in and CVL has not be reached.

The only way to reduce charge-current is to set down CVL - your BYD seems to do it, the Seplos do it not (maybe with an update because i wrote them that it makes sense 😁)

You helped a lot!

One thing that would be nice to know if the BYD-battery really reduces CVL when for example on cell gets over a voltage-limit, but then you have to disbalance one cell 😅

For me it is no problem when this safety-feature don´t work with the seplos because I only charge up to 55,2V (3,45V per cell) - so I protect my battery and I will skip the last few Ah of the capacity.

Once or twice a year I will charge the battery full and then slowly go up with the voltage to 3,55V or 3,60V per cell to do a clean top-balance and "update" the real SOC

Where is the best place to buy one of these now? Just about to pull the trigger and buy batteries from oye too.