This site is now in read-only archive mode. Please move all discussion, and create a new account at the new Victron Community site.
ESS system, MP 5000/48 in 3 phase, with 1 grid tied solar system, and 2 MPPT's connected to the battery, mppt's connected with VE-direct.
The mppt display shows they have external control. However, when the mp2 goes into absorption, the mppt's continue to charge in bulk. I have checked this with disabling the charger from the mppt's. Any reason that can cause this?
still no solution? Bms control is enabled, but mppt's keep doing their own thing.
In ESS Bulk is the preferred state (during the day) as they are bulk producing power for loads (whether local or export). If they went through the charge states as the batteries are in, then you would have to wait for the battery to drop into rebulk voltage before they began producing again. So not desired in an ESS system, as the point is to keep batteries charged and cover loads with solar.
So the batteries (as shown by the inverter) are in float, absorption idle or whatever but the mppts can cover loads fully no battery or grid used. A well sized system can cover loads entirely by solar not touching the battery or even grid. My system always pulls about 108W from grid as we are not allowed to feed in.
If your loads drop down, the mppts will ramp down and not overcharge your batteries so the batteries are still controlling their charge in that regard.
Issue is the bms is telling the multiplus units to charge absorption, and the excess power goes into the grid. This is perfect, but the mppt's keep charging bulk. I would expect them to do the same, as it should be considered as one system, all connected with ve direct and slave.
The mppts are supplying bulk to the grid are they not? They are not charging the batteries on bulk they are supplying bulk power to the grid. So you need them in this state.
They are not in absorption but your batteries are, this is correct. Since in absorption stage the batteries don't really take in current at all, if you wanted them to be in the same state they would stop producing as much. If you stop feeding to the grid then you will see absorption lights on the mppt of you have no loads in your system.
As soon as a big load comes up in the system, they will switch to bulk again. That is the beauty of ESS assistant.
so essentially the mppt's charge to a higher voltage compared to the mp2, while all controlled by the same bms
