We have a MultiPlus II GX with a SmartSolar 150/45tr rev3 and 2 x CS 585W panels in series feeding the MPPT. The Battery is a Pylontech UP5000 battery connect via CANBus to the Multiplus II.
This Off-grid installation is 6 months old and worked as expected, but over the last 2 weeks, intermittently stopped charging the battery. The MPPT shows it is externally controlled
The MPPT has an interesting PV voltage graph when it stops charging. (See below) While the current in and out of the MPPT stays 0Amp, the Panel voltage drops to ~58V. This I don’t understand, since the only way to pull a Panel’s voltage down, is to draw more load than it can supply.
Your mppt is programmed for 16 cell batteries, the pylons are 15 cell.
Under remote control it shouldn’t really matter, but, who knows.
If you’re offgrid it doesn’t really make sense to set the charger to remote controlled, the charger will never produce more current then the batteries can handle, if your settings are ok the battery will charge correctly.
I don’t know what happened, but just disconnect the ve.direct from the mppt, set the correct values for your batteries and set the charger to local control.
Start by documenting your setup and settings more thoroughly.
There is no need to start unplugging things.
Start with the basics again and step through your setup according to the doc:
What is the battery SOC when this happens?
What CVL and CCL is it sending?
Are there any variances in cell min/max voltages?
Have you checked all connections to make sure there isn’t an intermittent fault?
Any modifications or assistants loaded?
Any settings changed in DVCC?
Yes you should manually set the correct parameters in all chargers, but under external control they are mostly ignored, apart from current limits.
Here is the info
SOC - The drops to 85% is the normal operation as for the last 6 months. Two drop down to 60% and No to below 40% is the problem times
We are not onsite at the moment, we can only get to it Friday. IT was installed 6 months go and until last week, never had this issue. There is not people at the Bush camp for at least 3 weeks.
No assistance loaded, it had ESS loaded but we have since removed it.
Nothing obvious in the file, your float voltage is a bit high, should be 51V not 52V.
With Victron connect over VRM, you can change your MPPT charger preset (if it isn’t set to lithium) just to eliminate that, and other variables like temperature compensation, though this should be overridden.
The cell voltages show a large imbalance around the time when your issues started, so that looks like a factor.
Have you verified that the individual voltage readings, ideally taken with a meter, all agree between multi, mppt and battery?
I guess I shall have to wait until we get onsite Friday, and do some measurements.
Thank you confirming I don’t have something obvious wrong on a setting.
A site inspection showed that we had a bad connection on the Solar Panel positive + cable.
Once this cable was replaced, the system was running normally.
