BMS Image


Battery power not stable when battery is full and excess power is fed-in


I have a MP2 and a MPPT 150/35 with 2kWp solar power. I have connected a 14,3kWh battery with Seplos BMS. I charge the battery to 55.2 V and then after about an hour at 55.2V, I bring it down to 54V for the rest of the day. As soon as the battery is full, the excess solar power is fed-in to the grid.

I recognized that if the power is fed-in, the battery power is often not 0W as I would have expected, but alternates between charging / discharing with power up to +-/ 200W instead (charge / discharge cycles).

I use DVCC with voltage sense and already tried to use the MultiPlus instead the BMS as battery monitor.

Are there any suggestions or tipps to become the system more stable if the battery is full?

Thanks and regards





blackmarlin asked
blackmarlin answered ·

3 Answers

VTAC Battery current wrong direction

I just added a VTAC Battery to my System. Everything works out great, the Battery is recorgnized as LG Resu. The only Problem is the current flow direction in venus charge is shown with - and discharge as +. Is there a way to change this?



stagepower asked
andre-godinho answered ·

3 Answers

Victron & EMUS-BMS G1

Hallo, (english below)

ich weiß, das war schon öfter Thema, jedoch ohne Erfolgbringende Antowrten.

Ich versuche ein EMUS-BMS mit dem CCGX zu verbinden. Was muss ich beachten?

Gibt es hier jemanden, bei dem es funktioniert? Ich habe meiner Meinung nach alles richtig gemacht.

- Busabschluss gesetzt

- VE.Can auf Canbus BMS umgestellt

- alles auf 500kbps eingestellt

Und mehr kann man doch nicht falsch machen oder?

Zur Info: Ich benutze einen CAN-Filter von EMUS

Hi everyone,

i know this has been discussed more than once, but no result could help me.

I would like to connect an EMUS G1 with a CCGX. What do i have to consider?

Is someone here where it works problem-free? I think i make no mistake.

- BUS termination on both sides

- set VE.Can to CanBus BMS (500kbps)

- change CAN on the G1 to 500kbps

- use an CAN-Filter from EMUS

dischargetommy asked
dischargetommy commented ·

1 Answer

E-BOX-48100R-C wrong SOC value

ESS System:

2x E-BOX-48100R-C - FW: v105.0

1x SmartSolar MPPT 250/60-Tr

1x SmartSolar MPPT 150/35

1x MultiPlus-II 48/5000/70-50

Early at morning I usually have about 20% SOC left. When the Battery is charging I noticed that it charges above 50% SOC with a insane speed. From 55% SOC to 99% SOC (~ 4,5 kWh) in about 30 min. That is not possible There is no power source that strong.

further Investigations:

1. after reaching 99% SOC Battery draws still 25 A of current for several hours then reaching 100% SOC and stops charging. The calculated energy makes sense.

2. when reaching ~95% SOC (to early) the BMS reduces the CCL (Charge Current Limit) to 25 A.

3. the voltage rises from (to early) 99% SOC (~53.9 V) to 100% SOC (~56.7 V) quite a bit

So I make the assumption that SOC calculation in BMS Firmware is incorrect.

Does anyone have a solution for this? Has anyone experienced the same?

Regards, Andreas

wima2 asked

0 Answers

Buck boost settings wrong?


I have setup the following system:

Victron Buck boost connected to car and lifepo4 Victron smart lithium 100ah.

Smart shunt and bmw712 installed..

Ve.bus BMS installed

Here’s the problem. When I connect via app to the battery, my lithium battery has 13.5 V already.

With ts config I have set a full battery voltage of 13.2V, charging Voltage of 14.2 with 40A. Unfortunately the buck boost switches on and keeps charging. I am afraid I will damage my battery.

The green wire is connected to the vE.Bus BMS at charge disconnect pin.

What did I do wrong?

I have enabled the bms in ts.config. Since then the checkbox for the green wire is greyed out. Should I disable this and check the green wire checkbox instead manually??

Please help

eikone asked

0 Answers

Disable BMS Control in DVCC

Hello ,

Where is the BMS control function?


This is a screenshot from Andy...

My version :



I Can not find this setting anymore ...

Kristof G. asked
dadeppa commented ·

4 Answers

Use of BMS-12-200 with 2 alternators in catamaran

BMS-12-200-question.jpgHi there,

I am interested to use the BMS-12-200 in a twin engine catamaran installation where the owner is upgrading the house battery bank to LiFePO4 batteries, and wants to keep using his regular engine alternatrors with internal regulators to charge the house bank while motoring, but without risk to his new Lithium batteries.

My question is, could we use the setup shown on the BMS-12-200 datasheet but with a two way selector switch instead of the simple On/Off battery switch shown in the diagram. Each alternator would be connected normally to its own starting battery, and we would run separate output wires to the BMS-12-200 with a selector switch to connect the charge coming from the engine running at any give time.

Many thanks for any comments or answeers.

luis-manuel-pinho asked

0 Answers

Pylontech RT12100G31 Installation and Integration with Victron CCGX

I have recently installed 8 x Pylontech RT12100G31 as a single 800ah 12v battery bank. The batteries are working (charging and discharging) and are interlinked for balancing. They show up correctly as a single bank in the Pylontech bluetooth app.

However, I have not been able to get the batteries to communicate with the CCGX. The CCGX is on the latest firmware (v2.92) and I have have a victron terminator in the other VE.Can port.

There is very limited information about these batteries online and unfortunately the instruction manual is very limited. I have used the following links for reference:

I have wired the comms cable using the type B Pinout in the first link above as this matches the batteries instruction manual as below. I have tested the wires in the cables pin to pin to confirm continuity and correct pin matching. This has proven correct ... multiple times. I have also removed the VE-Can terminator and confirmed it has continuity and resistance of 120 ohms between Pins 7 & 8.


The table above shows Pin 7/8 being for RS485A /B. I have not wired this as it does not seem to map to any wire in the Victron VE CAN-bus RJ45 terminator and I know others with working integration between the same pylontech batteries and a Cerbo without this wired.

The documentation suggests that once correctly connected, configuration will occur automatically, but I have also tried manually turning on DVCC and configuring the VE CAN-Bus profile. I have tried all available profiles without success although I believe the correct one should be Can-bus BMS (500kbit/s).

Has anyone succesfully connected these batteries to a CCGX and can advise on what I could have wrong? Alternatively, perhaps someone with experience in connecting a BMS to CCGX can help?

daveh-1 asked
Mark commented ·

3 Answers

Seplos BMS


I am looking at the Seplos BMS 200a 16s.

Does anyone have any experience good or bad with this BMS and connecting via CAN Bus to a cerbo GX.

Many thanks,


richie-gorrod asked
jeanmarie commented ·

3 Answers

New blood needs sanity check. - Using Victron MPPT & Battery with Synapse 3.0+ inverter



I am just starting out in he PV / Backup system world and would appreciate it if someone would let me know if my plan for a system upgrade makes sense.


My existing system is made up of a Synapse 3.0+ inverter with two lead-acid batteries in series to provide a small amount of backup power to a fridge, PC and some lights during rolling blackouts. I'm South African and, for someone who doesn't know, we have frequent scheduled blackouts (3 a day for 2h30m lately).

The Problem:

The batteries are now showing signs of corrosion and have lost most of their capacity. Many days there isn't enough time between blackouts for the batteries to recharge fully.

My Goals:

1) I would like to keep the Synapse 3.0+ to charge my batteries from grid at night time after a blackout.

2) I want to replace my worn batteries with Lithium for greater DoD.

3) I want to add PV solar to my installation to allow the new batteries to get at least 1 full charge daily.


My Proposed Solution:

The picture at the top of the post is a simple diagram of the changes I'd like to make to my system.

The first problem I have is that my roof is almost completely East/West facing. This means I need two strings on my roof to get the required coverage during the day to ensure at least 1 full charge per day. My plan at the moment is to have 2x360W (40.4V Voc, 11.4A Isc) panels per string.

Herein lies the second problem: The Synapse 3.0+ only has 1 PV input. This means that I need to get an additional MPPT to run the West string. For this I am looking at the Victron SmartSolar 100/30.

For the battery I am thinking about going either with 2x LFP 12.8/160 or 1x LFP 25.6/200 with the smallBMS for management.

My Question:

Does the diagram make sense as a system that will function as intended? Is there a better design that is maybe cheaper?

Also, I have been told by a supplier that the additional MPPT will only charge the battery and won't provide power to the Inverter, is this right?

Any advice and/or link to a similar functioning design would be greatly appreciated.

atloubser asked
kevgermany answered ·

1 Answer

Smart BMS 12/200: ONLY Alternator shut off possible?

I have installed a Smart BMS 12/200 with a Smart Lifepo4 200 AH and a starter Battery (Victron AGM). All charging (solar, power, alternator) goes directly to the AGM-Starter battery and then connected to the LifePo4 via the smart BmS 12/200

I expected that I can switch off ONLY the „alternator“ (so I can switch off all loading currents coming from via the starter battery) with VictronConnect or with the „Remote“ switch in the Smart BMS.

In the „Demo“ version of the Smart BMS 12/100 you have exactly these two options: a) switch off the alternator or b) switch off the whole system.

In the smart BMS 12/200 you have only the options: a) switch off alternator AND system+ or b) switch off all.

I can’t see the difference with these two options and I want to switch off ONLY the charging (via alternator/Starter battery), but not the whole system/the smart battery via system+

Any ideas? Is that a mistake in my system/in the BMS? Or did Victron changed some options from Smart BMS 12/100 to the 12/200?

Unfortunately the description for the Smart BMS 12/200 is not clear:

„Der ferngesteuerte Ein/Aus-Eingang steuert das Laden über den Wechselstromgenerator. Im ausgeschalteten Zustand ist das Laden über den Wechselstromgenerator deaktiviert. Die BMS-Funktionalität bleibt jedoch aktiv, sodass alle Lasten und Ladegeräte unabhängig vom Zustand des ferngesteuerten Eingangs weiterarbeiten können.“

Christian Ide asked
philiplyra answered ·

3 Answers

Battery current reading reverse of DC system current with REC-BMS


I have a REC-BMS communicating with a Cerbo GX over the can bus. (side note, for anyone else trying this I had to ignore the manual and use the VE bus rather than the can bus, and to set the speed to 250k instead of 500k)

The BMS has a shunt resistor and there's only one place the current is measured. The data is sent over the VE bus to the cerbo gx. While discharging, the battery current says it's charging and is the exact opposite of the DC system current. DC system current is the correct sign.

I just updated the firmware on the Cerbo GX to V2.94 and the issue persists.

Any thoughts?


woody06 asked
woody06 answered ·

1 Answer

Batrium + Victron + CerboGX- What is controlling my charge ramp down? (ESS)

Hoping someone can help. Ive been searching the web, forums etc. for a answer to my question.

Im charging my pack to 54.0 volts. When i hit that, at some point, the victorn system will add 0.4 volts to the 54.4 volt since im exporting excess solar to the grid.

However it will keep charging at 54,4 volt for some time, serveral hours at around 30-40 amp until my soc hits 100% in the batrium system (99% in victron) and finally it ramps down to 3 Amp.

My batrium remote target is set for 54.0 in normal/100AMP and 54.0 in limited, 1 amp. But when i hit 54,0V it keeps going and slowly ramps down to 30-40 amp, and when i hit soc 100 it will return to 3 amp. I dont understand why. DVCC is enabled, so i assume my MPPT charge values are ignored, aswell as my Multiplus-II values set in Veconfigure. So something else is controlling this ramp down effect.

To my understanding victron doesnt care about set Amp values when i use DVCC, it only cares about voltage, but what defines my absorption charge time then????

Hope someone can help. Im afraid im charging my battery to 100% and i dont want that.

m1kkel asked
m1kkel commented ·

1 Answer

Victron LFP battery question

Usage: small travel trailer, moderate usage but needing more power to get through nights running danfoss chest/cooler fridge (outside) and inside small danfoss fridge, when it's hot out. Plus lighting, and charging up various other bits.

I've currently got a BattleBorn 12v 100Ah battery, and I'm looking for 200+Ah (not going to describe fuse setup, it's sufficient with fallback Class-T at the battery). I'm contemplating switching to Victron LFP so I can tie into the rest of my current Victron systems (BMV-712, MPPT 150/50, Orion Tr Isolated 12-12 18a) for monitoring/etc of the battery, which BattleBorn doesn't have, which would be a nice to have.

I could just add a 100Ah BattleBorn, or upgrade the newer 270Ah BattleBorn, but the monitoring/integration could be nice.

However, upon reading closer, it looks like the Victron LFP doesn't have an integrated BMS in each battery pack? But it does have in-pack cell balancing? I'm getting confused now, so it had no built-in protection at all from over-current or over-voltage or anything like that?

So I'd need both a Smart BatteryProtect as well as a BMS, such as smallBMS or VE.Bus BMS V2. Seems overkill for my system, I'd just like cell health monitoring and such, but seems like Victron isn't for small systems with limited space :(

drizzt321 asked
klim8skeptic commented ·

1 Answer

BMS shutdown and system powered by solar?

I just manually hit the off button on my REC Q BMS. CLANK went the contactor, stuff started beeping for a few seconds, then everything came back online with the battery disconnected. I did not expect that!

This system is a Cerbo GX doing DVCC, REC Q BMS, SmartSolar with VE.can, and a MultiPlus.

So the default is to keep the system powered up from Solar if that’s sufficient for the loads? I’m amazed. Can this be changed?



Adam Sherman asked
klim8skeptic answered ·

1 Answer

980 Posts
674 Users

Topic Experts