I have got Multiplus II 48/3000/35 that can charge a battery with 35A current.
At night from 23:00 to 7:00 we have lower price for grid. So, I’ve started DESS with the main goal to shift consumption from grid to these cheaper night hours.
DESS creates a plan for the next day and every day it planning to charge a battery at the last hour of night - from 6:00 to 7:00. And the main issue is that it is forecasted to charge the battery with power as 2.5 or even more then 3kW in this last one hour of night. However, it is impossible because this Multiplus can charge the battery with power not more then ~2kW (max 35A x 56.8V).
As a result, it can’t charge a battery for the level, it estimated, and does it hour by hour during a day when grid cost is higher. This behavior is quite strange for me.
DESS manual says in “Step 2: Battery” topic: Maximum charge and discharge power - This is used for determining the maximum amount we can (dis)charge the battery in an hour
Now I have set my battery real (dis)charge values - 0.5C for 280Ah battery.
If I set 2kW for Charge Power, will my PV controller’s charge power be included in this amount? Or PV is out of this parameter and this value used for charge from grid only?
DESS requires the value with which power the battery can actually be charged and with which power the battery can actually be discharged.
Both run exclusively via your Multiplus II 48/30000 with max. 35 A. I.e. approx. 55V * 35A = approx. 1.76 kW.
Surely your PV is AC-coupled and does not charge directly into the battery? Therefore, it has nothing to do with the battery charging/discharging capacity
As soon as everything is running as expected, you can activate the balancing if you like. However, I would do this at a time when experience has shown that there are almost always cheap buying times.
I have activated balancing on a Sunday at 02:00 am with an interval of 28 days. This means that in winter (when otherwise 100% SOC is never reached) every fourth Sunday at 02:00 am is fully charged from the grid. Experience has shown that this is usually the cheapest time in winter.
