I have a new installation on my catamaran with LYNX BMS NG, Battery Bank Lithium NG and two Orion’s which are loading from the alternator the lithium NG Batteries with 50A max. The orion’s are connected to the BMS.
With running engines the orion’s lose immediately the BMS connection and don’t load the Lithium’s. During running engines i switch off the orion’s and then they are back in the BMS. When i switch them on again, they load the Lithium’s for several seconds. Then the orion’s say FLOAT and don’t load further. Ad they disconnect again from the BMS. Newest firmware installed.
There was a firmware update very recently to solve an issue where charging sources would be turned off when other charging sources are operating.
The changelog says this was fixed in v 3.70 in feb 2026.
DVCC:
Fix bug causing a system with a Lynx Smart BMS, and Lynx Smart BMS NG, to stop all chargers, instead of only those configured to be charging the main battery bank (System instance is the same as the GX)
My guess is your system is using DVCC.
So first perhaps upgrade your cerbo to latest firmware.
This did improve things for me.
Also note that if your batteries are full (indicated by float) then DVCC controlled by the BMS and the Cerbo will stop the chargers, so it could also be normal situation. If your Cerbo display says batteries are not 100% but your chargers are all in float then you may need to sync the State of Charge (SOC) to 100% to make the Cerbo know that the batteries are full. I have had that too. Check also in cerbo that your batteries are all balanced.
I find the Cerbo Display more useful than the victron connect for system overall status
(all the above assumes that there are no wiring faults / loose connections etc)
Sorry, I also see the BMS connection was lost to the Orion. Can you explain exactly how they are connected? The ve.direct cables can fall out of the Orion or the cerbo, so check those.
If you are using a USB hub to connect them make sure the hub has good power.
Your cerbo screen should look like this, with the Alternator block, if it doesnt then your orions are not connected to the Cerbo/BMS, then when you tap alternator, you should see both Orions even when the engines are turned off.
Mine are configured like this to see the alternator block, if you are charging with orion XS from alternator I advise that setting.
The Orion XS does not use ve.bus, but ve.direct. If you are using the ve.direct to USB cable, please can you tell me if it is directly connected to the Cerbo, or if you have a USB extension cable, or if there is a Hub.
Again I strongly advise you to check if the ve.direct jst cable is correctly connected to orion, as they are famous for falling out. Please share picture of your orion if you can.
Yes all your things are up to date so the bug is not your problem. Looks like a cable connection issue. Either USB side or ve.direct side.
Assuming problem is not a USB or ve.direct cable problem, Do also try to reset the bms connection for the orion in the cerbo settings, and reboot the cerbo. As per below screensht:
You are right, ve.connect instead of ve.bus. Each ve.connect to usb adapter has an 2 m usb extension. I removed the original USB hub from the system. Instead, I installed two USB extension cables.
One thing makes me curious. Instead of putting the Orion on and off via victronconnect (which mostly uses bluetooth - or VRM) can you do the same control via the cerbo?
This will help us to determine if its a ve.direct / usb issue:
Yes, I can switch the orion’s directly via cerbo. As i wrote, as soon I start the engines both orion’s are going to float and are loosing the BMS. So I can charge the engine batteries but not the lithium NG bank. I read in other discussions that you have to disconnect the orion’s from the BMS. But that is not what victron recommends and from my point of view dangerous.
If you disconnect the Orions from the BMS, remove the USB cable and then control them by bluetooth from the victron connect app is OK. You just wont have any DVCC control.
In fact this is a good test to see if they charge well without any BMS, then you can try to add back the BMS.
For long term, you can connect a hard wire from the BMS ATC port to the port on the Orion, to make the orion stop charging when the BMS tells it to. This takes the danger part away.
But its not really a nice solution. When its working well, with USB, which it is for me, it is a nice system. Its worth to persevere.
How are your OrionXS’s configured on the Cerbo? Is it setup to as charging the main battery from an alternator (which is the correct setting in your case)?
So like this:
Hi Thiemo, my setting is this. The technician said that this is correct, because we we charge with the alternator the engine batteries and through the Orion’s the lithium bank.
