Feature request -- change to solar/wind priority in Quattro firmware (v552 now)

DIY
,
1

The solar/wind priority feature currently switches from Sustain to Absorption mode if a week has gone by without reaching 100% SoC, to force cell balancing. It then stays there forever instead of returning to Sustain mode.

Three feature requests:

  1. Make the time delay programmable – a week is shorter than many LFP suppliers recommend (e.g. a month).
  2. After a given period held at 100% (e.g. 2 hours – should also be programmable!) return to Sustain mode.
  3. Only trigger “Charge to 100%” if SoC then falls to a (programmable!) threshold (e.g. 50%) – and afterwards, return to Sustain mode

As the firmware runs now, there an be conflicts especially where an external BMS is the master – in my case when the Quattro triggers a “Charge to 100%” cycle it never gets there since the BMS is holding the maximum charge voltage down, so it stays in Absoption mode forever.

1 Like
2

What kind of system do you have?
The solar wind priority is not designed for system that are connected to the grid all the time.
https://www.victronenergy.com/media/pg/Solar_&_Wind_Priority/en/introduction.html

3

A narrowboat, which spends the winter plugged into a UK marina shoreline, like many others.

If the Quattro sits in Absorption mode all the time no solar energy ever gets used, which roughly quadruples the shore power use – presumably because the Quattro has much higher quiescent power than in Sustain mode.

With solar/wind working and the Quattro in sustain mode, average shore power is about 30W (0.7kWh/day) since most of the loads are DC, the AC is passed through from the shore to very small loads, and I assume the inverter is not running or in a “low-power” mode. Even in winter the solar panels can keep up with the DC boat power demand, the mains is only providing the small power to keep the Quattro alive.

With the Quattro in Absorption mode shore power is about 110-115W (2.7kWh/day), the inverter/charger is running all the time. I can see this from raised temperatures in the electrical cabinet where it’s fitted, the external cooling fans cycle on and off (controlled by the Quattro fan control, so these do too).

I still don’t understand why the solar/wind parameters such as intervals between 100% SoC charges can’t be made programmable, fixing this to one week makes no sense – also why once it has done this once it never goes back to Sustain mode, with programmable dwell time at 100% SoC and SoC level to restart shoreline charging.

This would make the Quattro much more usable in many cases – I know of at least two other people (with boats) currently suffering from what looks like the same problem, and that’s from a pretty small community (electric narrowboaters).

You can see the difference here – at the start the Quattro was in Absorption mode, then I manually cancelled the “Charge to 100%” via VRM and it went back to Sustain. Right now I have to do this every week… :frowning:

solarwind
solarwind1632×904 182 KB

1 Like
4

I’ve found that it is possible to change the Quattro “Charge to 100%” interval from 7 days, so I’ve set it to 14 days. Now waiting to see what happens – there’s been little sun lately so SoC dropped below 95%, at which point the BMS upped the CVL from 54V to 57.3V, which should mean that next time the Quattro tries to charge to 100% it actually does so…

5

And while Victron is at it : please cancel the priority rule if “charge only” is selected.

6

I have exactly the same use case but with a multiplus and an RV that during winter time is attached to mains most of the time.

All configurations parameters mentioned by @iand would make the solar & wind priority really usable.
Right now, in VE.Config I can only see 1 parameter. The sustain voltage.
That configuration page should be expanded with the extra ones to make the behaviour configurable.

Btw @iand you mentioned changing the time from one week? Where did you do it?

Regards
A

7

Because Ihaven’t actually tried this it may not work, but can’t you mix conditional ac connect and wind solar priority?

Or add a node red flow to connect on a schedule (A variant of this I have done)

Charge to 100% is setable in the charge tab - absorption/repeat absorption interval.

8

In the Quattro settiings – only accessible using VEConfig, not through the Cerbo or VRM – I thought you could change this in the “Charger” tab, “Repeated absorption interval” was set to 7 days, I’ve changed this to 14 days.

(if the BMS is triggering a charge to 100% this interval is controlled by the BMS and is set to 7 days)

However this doesn’t seem to have worked, the Quattro still triggered a “Charge to 100%” (and then stay in absorption mode instead of reverting to sustain mode) after 7 days… :frowning:

It seems that this interval for solar/wind priority isn’t affected by that particular Quattro setting, and there isn’t another one that sets it, it seems to be fixed at 7 days by Victron (which is what the solar/wind documentation implies).

==> Can anyone from Victron confirm this?

9

Changed that interval, it made no difference, still triggered a “Charge to 100%/stay in absorption mode” event after 7 days… :frowning:

(this was a reply to the post from LX which I expected to appear below it…)

10

Yeah discourse has a wierd way of ordering things. Still not used to it.
Interesting how there is no effect. I don’t leave mine connected for long enough to experience the same issue.
And if you shorten the duration?

11

I haven’t tried that, but there’s not much point – I don’t want the Quattro to trigger a “Charge to 100%” unless I tell it to. Or do you mean just to see if changing that parameter affects the period?

12

I thought so.
I guess the real only paramter we have to play with is the Sustain voltage.
All the others under the Charger tab are not used by the solar / wind priority :frowning:

image
image1260×934 47.9 KB

13

I am starting to wonder if things like limit charge voltage in DVCC and things like that have effects.
The feature request for longer than 7 days is an interesting one, i do see the reasoning. I don’t think there was a consideration for long term docking (i could be wrong, i am not part of a dev team). But wonder If a disconnect and reconnect will reset the 7 days? Like a combination with ac ignore/conditional connect (which i find easier to set in Victron Connect) or the dvcc cap will change things

I assume this is the part of the graph you are talking about?

Screenshot_2024-11-28-15-49-58-653_com.duckduckgo.mobile.android-edit
Screenshot_2024-11-28-15-49-58-653_com.duckduckgo.mobile.android-edit1080×887 60.6 KB

The other ones seem more related to pv.

14

@iand
Actually reading

3. Configuration at the bottom it says:

  1. Check other settings
  • If the storage setting is enabled, after 12 hours of float the system will go into storage mode as usual.
  • Repeated absorption interval: With solar and wind priority enabled, this setting controls both the duration of the initial Sustain mode and the repeated absorption interval. Increase this setting in case it is preferred to keep the system in Sustain for longer - allowing more days for solar and wind to charge the battery before falling back to shore.

so it seems that the parameters are there?

/Andrea

1 Like
15

That page assumes that the battery charging is controlled by the Quattro; in my case the external BMS is in charge of this so the sustain voltage has no effect.

If the Quattro does trigger a “Charge to 100%” (which comes up in red on VRM) after 7 days (should now be 14 days, but doesn’t seem to have changed) and I stop it manually afterwards then it does go back to sustain mode, but if I don’t do this it stays in absorption mode.

What complicates this is that since the BMS sets the maximum charging voltage, which in sustain mode is 54V (about 99% SoC), if the Quattro tries to charge to 100% on solar it can’t get there. The BMS changes Vmax to 57.3V when SoC drops to 95% (not much solar), so if the Quattro triggers a “Charge to 100%” after this it works. If it did this after 14 days (the repeat time setting in the Quattro) this would be fine, but it seems to still use 7 days… :frowning:

When there’s plenty of solar the BMS should stop charging at 54V every day, and then once a week allow charging up to 57.3V for 2 hours to reset SoC counting and balance cells. What was happening (and maybe still is) that the Quattro gets there first, then sits there trying to charge to 100% (57.3V) and failing because the BMS is holding voltage to 54V because SoC is above 95%… :frowning:

I don’t think Victron have really thought through how this solar/wind priority works in a case like this, especially where an external BMS is the master not the Quattro. I’m sure it could be fixed – maybe with some extra parameters which can be set – but this would mean Victron spending some time to do this… :wink:

16

Not sure how wind solar gets blamed for the battery request.

If Quattro is doing that, why is it doing that programming? The bms control should and does override it. Or you must change the base programming. Quattros don’t charge above set levels (barring a fault) unless the battery requests it.
What battery do you have?

17

That’s not how it works. With external control the BMS is supposed to be in charge, it sets maximum allowed voltage and allowed charging current – when the voltage limit is set it drops charging current to zero, which stops the Quattro (from shoreline) and MPPT controllers from charging the battery any further.

The way the BMS works is that if SoC is 95% or less CVL is set to 57.3V and CCL is set to 420A. If charge current is available from solar or shoreline the battery then charges up to 57.3V and is held there for 2 hours for balancing, and SoC is reset to 100% – at this point CVL is set to 54V and CCL to 210A, but charge current them drops to zero until the voltage falls back to 54V – at which point the charge current stays at the value needed to maintain this voltage, so long as a charging source is available.

With wind/solar priority, if solar drops below this current (e.g. when it gets dark) the voltage starts to drop below 54V until it gets light again, then the MPPT controllers provide enough current to get back up to 54V where charging stops. Shoreline power isn’t used because of the solar priority setting.

Then once a week the BMS raises the CVL to 57.3V, the battery now charges up to 100% SoC and stays there for 2 hours, then CVL is set back to 54V. This is what I’ve seen happen after a trip to get back to 100% SoC, typically this takes a few days.

Then for the next week SoC never hits 100% because the BMS is holding CVL at 54V. Now the Quattro solar priority firmware thinks "Aha, not enough solar power to get to 100%, better trigger a “Charge to 100%” (switches to absorption mode – which shows up on VRM) – but it can’t because of the 54V CVL, so it sits there using shore power in absorption mode. Maybe forever, I turned it off after a couple of days.

The problem is that because SoC never hits 100% (because the external BMS is holding voltage down) the Quattro thinks there isn’t enough solar power to charge the batteries, so switches to use shoreline – at which point no more solar ever gets used. But this assumption is wrong, there was enough solar to get to 100% but the BMS stops it being used because the sustain voltage is 54V.

The BMS would have allowed a charge to 100% after a week, but the Quattro got there first and then failed to do this.

If there really isn’t enough solar and SoC drops below 95% over several days, then the Quattro does correctly trigger a “Charge to 100%” from shoreline, but it then seems to stick in absorption mode – maybe I didn’t leave it long enough to see if it then went back to sustain mode, but the manual for solar/wind priority says that it doesn’t and stays in absorption mode.

18

The issue is what happens when the Quattro decides that solar/wind priority isn’t delivering enough power (because 100% SoC hasn’t been reached for the last week), so it switches to shoreline to try and charge to 100% (57.3V) – but fails because the 54V CVL prevents this.

It doesn’t recognise that 100% SoC was deliberately not reached because the external BMS only wants this to happen once a week for 2 hours, not every day – it doesn’t realise that this is the reason for not getting to 100% SoC rather than insufficient solar power.

19

Quote from the documentation:

When activated, the system remains in this mode, called Sustain, for seven days; if there is not enough sun or wind, a full charge cycle will take place, charging the batteries to 100%. This ensures they remain in optimal condition and are ready for later use.

After these seven days, the system will not return to sustain mode. Instead, it will keep the batteries fully charged and prioritise solar power over shore power wherever possible during the day to run DC loads such as pumps and alarm systems.

The problem is that most of the loads are AC so the solar is then pretty much turned off even though it could provide plenty of power during the day, and all the energy comes from shoreline and solar is ignored.

20

I think the way to fix this would be for the Quattro to decide that the batteries were full (from the solar/wind priority point of view) when the programmed CVL is reached not 100% SoC, and then switch back to sustain mode. With external BMS control it’s not the job of the Quattro to decide when they’re “full” (e.g. “100% SoC”), that’s the job of the BMS.