I could use some help here. I recently installed a Multiplus II 2x120 and now a CerboGX to adjust/monitor it.
The DC side of the inverter is connected to (4) 6V batteries in a series/parallel install so 12V and 450AH.
The config file for the Multiplus is basically stock settings with one exception, an assistant to keep the AC Out 2 relay active if the battery voltage is above 10v.
The problem I have is that the batteries are very low, VRM shows Idle / 11.73V and that they are 100% with 0 amps going into them.
I have the temperature sensor installed and I also have the voltage sensor installed. I don’t get it, if the config file is basically stock, why is it not charging the batteries?
You’re in bulk, that’s charging. It appears your charger setting might be set wrong?
Do you have a smart shunt to monitor the batteries? I’m not familiar with a system that doesn’t have something to watch them. I don’t know how the MP would know SOC.
You’d think it was charging but the voltage never increases. It thinks the batteries are 100% when the actual voltage is more like 25%. There is no shunt. I just spent $400 on the Cerbo. My guess is the battery voltage is coming from the V-sense wire I connected along with the V-Temp. So the multiplus does know what the battery voltage is.
Shore current is 30A pedestal and charge current is set to 120A. Basically, I reverted to the stock config settings to ensure I didn’t introduce a problem. As you can imagine, the lights are very dim in here and are flickering. I now know why I can’t seem to shake that migraine.
It always knows the voltage, its connected with the big wires. The sense wires just make up for any voltage drop. The MP can’t know battery current without a shunt or BMS. Are these lead acid or lithium?
You shore current limit is capped at 50A, it’s a setting in the Cerbo that might be set lower. If it’s set to 30A, you might have the charger misconfigured. If it’s at 10A, raise it to 20A.
I don’t know how to get at that setting in the Cerbo. I thought the VRM Portal would give me access to everything in one interface. The multiplus has been doing this for the past week, the Cerbo was just installed today. I’ve been talking to the seller and I’m pretty sure I will just be sending it all back and re-installing the old inverter. These flashing lights are killing me.
If you look at the picture closely above, you’ll see it is in bulk charging mode but nothing is going through to the batteries. At least, nothing significant. I’m going out in the rain to pull it and put the old one back in.
From the Overview, click on the inverter/charger card, check shore current limit.
I looked at your MP setup file, it should be charging. IF that shore limit is set close to the actual shore current, it will prevent charging. What’s that limit value set at?
I changed something in VRM (input current limit) to 25A - It is the multiplus that is set to that. I have no idea how to get to the Cerbo settings.
What software are you using in the first picture?
It still thinks the batteries are at 100% when they are at 11.58V
The lights in the unit are all 12V LED’s that run off the low batteries.
Update: I now have a charger on the house batteries and they are at ~12.23v yet the VRM portal reports them at 11.58v
I checked the voltage at the batts with a DVM and it also shows ~12.23v.
I’m wondering if the Victron inverter is defective….
Btw, this problem was present before the Cerbo was installed. The Cerbo was only purchased to diagnose this issue.
Update#2 - VRM is now showing the actual battery voltage that the aftermarket charger is putting in the batteries.. but it still thinks they are 100% full and so refuses to charge them.
The internal voltage control on the Multiplus is terrible, by design. Mine was off by 0.25 volts. I was quite shocked to discover this is considered “normal”.
I have a Smart Shunt which does have accurate voltage measurement. When connected to the complete system the voltage control is very good.
The bottom line is that the Multiplus needs something external in order to provide decent voltage control. By itself the Multiplus is almost not useful as a charging system. The sense wires do not help in this regard. They only correct for any voltage drop from the charger to the batteries, not for the overall calibration error.
This is horrible news. I just shelled out an extra $400 for the Cerbo to diagnose this issue. How can they sell an inverter/charger that doesn’t even charge??
I’ve got my batteries connected to an 3rd party charger in order to get them to charge…
The Victron sits there in bulk charging mode and does nothing…
I’m sending it back. I had no idea that Victron’s Inverter/Charger required more purchases in order to actually fulfill it’s mandate. Why don’t they tell people this in the brochures and advertisements? You know, something like Charging function is dependent on further purchases.
Or, this unit will not charge batteries without additional extra-cost purchases.
This really burns me up. I spent more than a week doing pre-purchase research on this inverter/charger and no-where in the documentation did it ever say that it required purchasing more items for the charging feature to work. I already contacted the seller about returning the item. I hope I don’t have to call Visa and ask them for a charge-back.
That’s more than a week of work and then the install and the removal and reinstallation of the old inverter just to realize it has no problem charging the batteries and then re-installing the Victron, only to find out it cannot even fulfill it’s primary design without buying more Victron….
Who is paying for all this wasted time and effort? Let alone all the people trying to help me determine why an Inverter/Charger will only fulfill 50% of it’s design function?
It’s a web browser with the interface to the Cerbo. If it’s on your WiFi network, venus.local might work, or the IP address of the Cerbo, or open the remote console in VRM as shown in post #4.
I question a battery at 12.23 volts that doesn’t draw some sort of current. My Multiplus is off by 0.030V compared to both my smart shunt and lithium BMS, not 0.25V or 0.35V. I doubt the MP is off by that much, and even if it was, it still should charge.
VRM might not be updating with your batteries that low? If you lost your WiFi, you wouldn’t have updates from the Cerbo, VRM holds the last readings, but does indicate when they’re last updated.
You have your MP set to use an external battery monitor. I’m pretty sure that is for an external monitor, try unchecking this box and see if it charges.
Hi Paul - thanks for trying to help me with this stuff - I know it’s been a hassle.
Removing the external battery monitor option didn’t cut it. I’m starting to think the previous post is likely correct, that the unit will not even charge batteries without an external shunt. The company I bought it from seems to indicate the same thing….
Which really makes me angry because if this is true then it would be false advertising, and then some. And as you can imagine, when I spend $400 on a Cerbo, just to diagnose this problem, then the idea of being forced into buying a shunt is probably the straw that broke the camel’s back. End rant.
I can get to the venus.local page but it wants a GX Password. So I’m looking at the sticker kit that comes with the Cerbo and it does not say, anywhere on it, GX Password.
I now have an external charger on the battery bank and it seems to be keeping them above 12.3V or about 70% so connectivity issues can be eliminated.
Update: It seems to the bluetooth password works but it takes me to a page that just says Loading…and doesn’t appear to go anywhere. I tried this in both IE and Chrome…
I just restarted the Cerbo and I’m seeing the same thing. When I use the web browser it takes me to a password screen, so there are not network issues. I put the bluetooth password in there and it then goes to a black screen that just stalls and says Loading…
I tried both IE and Chrome but it never gets past that.
