Hi all,
We have a nicely working 3-phase Victron system with MP2 and Cerbo Mk2 in DESS mode, also off-gride mode is working in case of power outage.
Next week Monday morning we have a planned grid power outage for 5 hours but normally during the morning the SOC of the battery is only 20%, not enough to overcome the 5 hours power outage.
Is there a simple way to force a SOC of 100% without changing a lot of settings?
Thanks!
There is a new way that works quite well: sometime Sunday afternoon you can set a (imaginary) EV consumption forecast starting on or just before the 5 hour outage is planned. See âedit forecastâ button in second screenshot.
Make sure to make it large enough, between 50% and 80% battery capacity.
And make sure in your DESS Power limit settings that the DC / Battery _maximum discharge power_ is equally large.
This will make DESS plan for that (manually) adjusted EV consumption forecast, even it is not actually going to be realized, DESS will still optimize charging up your battery to full.
I use this every day to make DESS expect a large (imaginary EV) consumption forecast at the end of today, to emulate the realistic expectation there will be ample sell opportunity tomorrow. This in turn ensures DESS starts charging early enough in morning (before the next day ahead pricing are known). Then in the afternoon I move that forecast forward a full day (delete today, set tomorrow). The forecasted EV consumption moment/hour is never reached, hence imaginary.
For me this hack/workaround allows to counteract that in the morning the DESS (trade) scheduling algorithm is always planning to reach MinimumSoC at the end of the known prices period today, missing all morning buy opportunities for selling back tomorrow. But your usecase is equally valid.
Which would require to:
OP asked for âwithout changing a lot of settingsâ and you and I have been discussing the underlying issue of porting the functionality to set custom a future SoC targets as input to the schedulers algorithm for ages now already dear friend dognose, that I wonder how much more proof you need to acknowledge the factual correctness of my thesis that minimumSoc needs to be decoupled from the SoC target at the end of the known prices period / a future planned moment.
My solution, as an indirect method of instructing DESS when to plan to have full batteries, does not require changing mode of operation, nor timing interventions. At least you can acknowledge the advantages thereof.
When? Thatâs the issue here. We do not want to have to time interventions. We want to set SoC targets in the future, and have DESS sort out the timing. As it is perfectly capable of doing, better than me myself I may add.
No, you need to change nothing. When you select âKeep Batteries Chargedâ, DESS will go inactive and ESS charge to 100%.
His question is not about forcing a 100% daily, but about precharging ONCE for a scheduled grid-outage.
Sorry, not every thread is about you 
Of course not, donât be silly. We are all the customers that could be helped with just one simple action from Victron: port the already existing b_goal_SoC / b_goal_hour function from Node-RED DESS to VRM DESS, no new development required, it sits right there waiting in the Node-RED DESS code and even VRM-API already has the addressable paths.
Doing so will enable OP of this thread, other people and indeed myself, to decide structurally or occasionally when we want our batteries at a certain SoC in the near future, AND HAVE DESS OPTIMIZE HOW TO GET THERE .
You are missing the point completely: the âwhenâ IS the point. Simple question: When should OP open VRM and manually set âkeep batteries chargedâ? One hour before, two, four, twelve, twenty-four? The whole point of setting a SoC target (or applying my hack that achieves the same), is not having to guestimate how many hours beforehand a timed manual interventions needs to be executed on the system. Being able to feed the scheduler the SoC target, and have it figure out itself how best to get there in time, IS THE POINT
But you donât have to believe me even, it would already suffice if could have a word with dirkjan about my bug report concerning setting consumption forecasts via VRM-API. Once that is solved I can build and publish a virtual b_goal_SoC/hour Node-RED flow, to help OP and many others achieve what Victron will not even consider to provide.
You are missing the point.
It is a regular system on a regular day and the question how to get the batteries to 100% one time, without sophisticated settings hacks, because there is a announced grid shutdown.
And then you simply set your ESS Mode to âKeep Batteries chargedâ the evening before and you are good.
And that is what âKeep Batteries chargedâ is exactly designed for: hold them at 100%, until the grid fails, then take over to supply the household during power outage.
Well, we donât need to treat this as a disagreement, we could see it as innovation and progress instead.
Yes setting âkeep batteries chargedâ is the obvious readily available option to achieve what OP wants, but will require OP to a) âdo the mathâ how much time ahead of the planned outage he needs to activate that option, for the system to actually charge to full. And b) make the settings change at that specific moment or earlier to be on the safe side.
And both of that can be prevented by making good use of the freshly released adjustable consumption forecast feature. It allows OP days ahead of the event, to set the amount and the moment the additional reserve energy is needed for the outage, and be done with it, DESS doing what DESS does best: plan and schedule an optimized SoC profile.
Setting a planned consumption forecast seems the better fitting solution to real usecase: 5 hours planned outage. All thatâs needed is to know when the outage starts and how much kWh needs to be reserved. Quite likely the battery doesnât even need to be charged to full.
Thanks @UpCycleElectric and @dognose for your replies.
For now I choose the simplest option to keep the batteries charged although the new option proposed by @UpCycleElectric is very interesting for the future in case we have planned âexcessiveâ loads.
