I recently installed a new system for a mate at his remote cabin.
Battery is a 48V BSL , we have a Cerbo , Lynx , Shunt etc.
It all worked fine, we had the software done by the supplier remotely and all good for a couple of weeks. My mate charges it with a 6KVA diesel generator which he’s used for years without batteries and it was my idea to get the inverter system so you don’t run a 6KVA genny to watch TV or charge your phone.
Anyway it’s stopped working with a “Low Battery” warning on the Multiplus. Battery has 5 ot the 6 SOC lights illuminated and the touch screen display shows battery at 83% and 50.4V. Done everything I can but it just won’t work. Contacted supplier but he’s very hard to get hold of for help.
I’ve checked everything and it’s all good as far as I can see. I did forget my multimeter so didn’t check the battery voltage but will head back up there to check it.
Any ideas. I’ll try and upload some photos of the displays.
I should say it is mostly used to power Starlink (100W 2 times/day for an hour at a time) ) so he can then connect to WIFi and access his CCTV cameras so it doesn’t have a huge load on it very often.
Starlink and cameras are on a timed 13amp socket and the Multiplus is left on always but idle.
Just checked battery voltage with my multimeter and getting 50.7V all the way into the inverter.
Hi ! As most BMS the SOC and LEDs are very inaccurate. At 50.4 volt the battery is nearly empty (for a 16 s pack). You have to recharge it via grid to 100 % (with the correct charger settings). Maybe your mate did not charge the battery to real 100% for a very long time ? Maybe the bms had no chance to balance the cells too. The pack should be charged to 56 volt and stay there for a longer period of time to balance.
No idea that a 48V battery is empty at 50V
Any idea why the display is saying 82% ?
Why hace SOC indicators if they don’t work ? I’d have thought they should be able to make something like that be reliable , I mean they did decades ago.
the problem is, that most bms are not able to detect very low current …. e.g. standy current of the inverters. This currents accumulate over time. Because of this the bms tells 82% while in reality the battery is empty. Charging to real 100% recalibrates the bms and everything is fine for the next week.
Ok I understand now I think. So what voltage should I tell my friend to put the generator on ? He can do it remotely once we sort this out but for now he has to go there and switch it on.
It was all programmed remotely by the supplier of all the kit (Energy Monkey)
He configured the battery and said were good to go and it worked fine for 3 weeks now it’s off. Just spoke with friend , he is going up there tonight to put the generator on and leave it at 100% for an hour or so.
Normally, the installation company would have to take care of this. What do they say about the problem?
In order to be able to provide you with qualified assistance, we would need the complete programming for Multiplus and Cerbo GX.
@Meine_Energiewende said that the batteries first had to be fully charged. Especially with brand new batteries, it takes time for the individual battery cells to balance themselves out.
As many have pointed out, you need to provide more details about the system, especially the components and settings. I also have 48V BSL and Cerbo GX but none of your problems. My system has been running reliably for more than a year.
You can get the settings from VRM or the VictronConnect app. Battery, inverter and some Cerbo settings are key.
I had a low battery issue which was promptly cured by restarting the system.
How many battery modules do you have? That could be inadequate even when your loads are low.
You mention that you have a shunt but I see in the pic CAN also connected (I don’t use any shunt). So what is selected as the battery monitor in the Cerbo? A shunt may need initial calibration with the battery (if it is the battery monitor).
In my experience, take time to understand how your system works. Don’t blindly follow installers or agents, though they can help.
We left the generator on all day yesterday and it eventually went up to 100% and 54V
I’ve got a phone meeting with the supplier at 2pm today to go over it again with him but hopefully it’s all good , we just need to know when to put the generator on and it looks like Battery SOC is useless as an indicator so do we just use the Voltage ? If so when ?
The next job was to use the Cerbo to remotely start the generator as it already has a 2 wire switch in the cabin to start it there rather than going up and starting it manually.
My supplier (Energy Monkey) has confirmed what is thought on here, that is that the current draw (1amp) is not enough for the BMS / SOC indicators to work properly , it can’t detect it.
So he has suggested I connect up the auto-start relay to the generator and have it start at 52V (before the inverter is triggered with a low battery) , then charge back up to 100% and switch off automatically. As long as it has diesel it should work fine and still only use a very low current and last at least 1 week between charges.
Obviously the Starlink is needed to switch on the generator using mobile app.
Yes of course you don’t need Starlink to start the generator …that’s good news. It does have a Smart shunt already , maybe it needs a different type , they did do a few changes to it today although I don’t know what.
Can you remind me the max Voltage at 100% charge? is it 55V ?
I was going to set the generator trigger at 52V as 51V is when the Inverter low battery is triggered.
