Hi, yesterday i installed a victron multiplus ll and after connecting batteries and Ac it will not turn on.
I had a brief flicker of lights at the front and now nothing.
This is now the 3rd time installing one of these units and never had this issue.
I have also tried connecting MK3 but cannot get a connection either.
The remote plug is in and jumper wire in tact.
Has anyone got any idea why this could be doing this?.
What battery are you using? Did you precharge the inverter? If it's lfp, best check the BMS didn't protect.
Does it do the same with no mk3 or gx attached?
Using lifepo 4 48v ,
With regards to pre charge I connected up the batteries first to the invertor.
I have around 52 volts at battery terminal connections on inverter.
Precharge means using a resistor or mppt to charge before connecting the battery.
The surge from the caps (even when the inverter is off) can knock many an LFP over as it appears like a dead short to the battery.
That there is voltage doesn't mean the BMS will allow discharge, it would be a good idea to check the BMS and see what it is telling you.
DOA inverters are rare, it is far more common to be a battery issue, so this should be eliminated first.
LFP is a chemistry, which model of battery is it? Makes it easier to check specs.
I will check that, should the invertor be able to turn on via the Ac though?
I will let the Mppt charge the battery today to see if it turns on the BMS.
The Batteries not quite sure they are not victron, they are single 16 single cells made up in a bank.
I have installed it on friends house. Which is the same as my house and another member of the family property.
Which is why it's thrown me a little as never had this issue.
I am hoping your diagnosis is correct with regards to the BMS not on. As we finished it late last night so the mppt charger were not working, meaning that the BMS may have not turned on.
There have been rare occasions where something has become loose in transit, so you could also pop open the cover and check.
The BMS seems like it is working as I can connect through the app.
The batteries got a full charge today through the solar.
I am starting to think if it's a BMS problem and maybe it has gone to sleep.
Have you any more ideas or do you think it could be faulty inverter?
It’s unlikely, never impossible, but unlikely. You did check the screws are tight on the remote jumper wire?
Are you able to connect to the bms at all?
It you set the inverter switch to charger only does it do anything?
Do you have another battery you can try?
It is not a victron BMS it is Daly one.
I can connect to the BMS via Bluetooth.
And when switching into charge mode it does the same thing.
I do not have another battery unfortunately.
I was thinking of maybe connecting it up without the BMS just rule out the inverter being faulty.?
Connect it parallel with the switch to the inverter, after a few sekunds you have precharged the capacitors in the inverter, and can turn on the switch
When you connect the bulp parallel with the battery switch, there Will go a current through the bulp that will build up voltage in the capacitors that is inside the multiplus. When the voltage in the capacitors is up, it will only take a couple of seconds, you can set the battery switch to on, and there Will be no surge of current into the multiplus because the capacitor is already charged. You can then remove the bulp. It is simple and required because of the nature of capacitors
