I bought a Multiplus II 48/3000 GX 2 months ago.
Everything was working fine with Firmware 2.51 in a way that too much energy produced from external Solar Inverters behind the Multiplus (AC side) have been used to load batteries instead of feeding into the grid.
With Fimrware 2.52 I realized that only PV Power directly connected to the MPPT of the Multiplus is used to charge the batteries and all Energy from other Solar Inverters are feed into the grid although the "setpoint grid" is set to 0 Watt.
My goal is to use the included DC Charger to load batteries as well from external Solar Inverters to charge batteries, e.g. when the weather conditions are bad and the MPPT connected panels are not sufficient to charge my batteries.
That said I downgraded to FW 2.51 again, switched the Multiplus off, waited 2 minutes, switched it on again and everything worked like before.
Seems to be a bug in the 2.52 FW. @Victron team: Who can look into this?
Thanks!