Since net metering will stop in the Netherlands at 2027 and we now have to pay €0,115 to € 0,145 for each kWh pushed into the grid, I am done with companies trying to harvest my money .
My current system excists of 3 x MP2 5000/48 in 3fase setup, a Smartsolar 250-100 and a Cerbo GX MK1 controlling all. In total 27 365Wp panels are connected to two Fronius Symo inverters connected at the backup output of the Victrons.
The strings can be adapted from (now) 10, 12 and 5 panels each to 5 x 5 and 1 x 2 panels.
I assembled my own batteries in two paralleled banks with each 18 EVE LF280K cells in series instead of the normal amount of 16 cells. All is running fine at 60-61Volts when fully charged.
I will extend with two extra 250-100’s, a 150-35 Smartsolar and 2x18 EVE LF280K cells (65kW in totl).
My question is: Can the Smartsolar 150-35 run fine on 62V like his big brothers can?
If yes, I will run totally from batteries in summer and can charge my car in the evening without any euro fine paid to the energy companies because I am feeding in.
However, using the Demo mode of Victron Connect for the SmartSolar 150/35,
setting User Defined battery type and Expert, I am able to set the Absorption voltage to 69.56V. Hopefully demo mode reflects the actual product’s capabilities.
Many thanks!
I will ask them upcoming year.
otherwise I’ll need to switch to 3 x 4 panels in parallel, using the full capacity of the 250-100.
Need to place string fuses hwever which set me bacj €90 for 6 pcs…
Not exactly an answer to your question, but…
If you take a look inside different Victron products, you will see that the DC capacitors are 63V rated.
Keeping capacitors near their voltage limit is not a good thing and invite problems, especially during high DC ripple currents.
Many thanks for all the honest technical feedback!
I just decided to revert back to 16s setup.
18s sounds good and deliver more kWh per battery bank (plus a lower current too) but the huge incompability with almost ALL bms developers and the possibiliy to make 4 12V units consisting of 4 compressed cells each weigh more on the flexibility scale. I even can make 2 spare battery units with the ordered 40 cells or make a backup system if the main one fails
Working on designed voltages is also a plus.
I showedhowever that working on 18S arrays is possible but in the long term it might let me run into problems I don’t want in future. Or not
In both the 250-100 and the MP2 5000/48 as well, the allowed working voltage is 66 Volts so it CAN be done.
Looking at the smaller 150-35 this might be a step to high however.
@alexpescaru What equipment did you open to see this?
It would be strange if Victron would take the risc of devices going south, working within the allowed voltages.
I wil check my pictures of the opened 5000/48 to veryfi
I won’t sue you
This is the voltage for equalizing from the smartsolar 250-100.
I cannot imagine victron selling stuff that isn’t approved at all withinn the range.
Since I keep below 3,5Volts I never reach the 61Volts so 3Volts below the max adjustable charge voltage.
My batteries never reached 1 Volts.
Victron putting 63Volts capacitors in a device that can charge to 54,7 Volts would be insane…
Although: Victron still sells Lynx systems with mega fuses that aren’t flambow resistant at 48Volts…
My problem is that Maximum Battery Voltage is not specified in any MPPT Data Sheet or Manual, you have to infer it from the settings that are available (e.g. 69.56V in Victron Connect).
Victron is normally pretty up front about maximum specs, but not in this case.
At least the label on the Multiplus-II explicitly lists 66V.
However, if that is Maximum Absolute, you don’t want to get anywhere near that.
I appreciate the community giving you fair warning, but it would be nice to get an official maximum voltage for both devices and what the risks are from Victron.
Maybe a stupid question, but why would you go and change the setup of your solar panels ?
In the GX settings you can disable grid feed in.
If your Fronius inverters are connected to and recognized by the GX, they can be throttled down in order to not feed to the grid.
As above, why not simply disable feed in?
I’m running eve 280k 18S / mk1 jkbms / mp2gx/ mppt’s 1no.150/35 + 2no.150/45. Has performed faultlessly for a few yrs.
So happy to receive a reaction from someone who’s using the same 18S setup!
The two Fronius inverters deliver a very nice efficiancy of about 97/98% when delivering PV energy to the grid. So far I agree with the setup.
BUT: charging batteries over a toroidal transformer with power electronics will cost you about 10% at full speed and transforming it back up to 230V from a 61V battery will set yo back another 7%
I talked about this with one of the Dutch Victron guys who should know this and thought to enhance the charging eficiancy to 97+ % using a SmartSolar, much more close to the battery voltage and NOT using any transformer between DC panels and DC batery.
Then I’ll win about 7-8% and also being able to spread the PV loads nicely over 3 pcs 250-100 SmartSolars AND a Smartsolar 150-35 for the remaining 2 panels
Looks lovely too this array of SmartSolars above an acoustic shielded set op Multiplus units.
Batteries will be placed on the roof between our house and the one of the neighbours so when having one meter of water flood, we still manage to keep stuff running.
I agree that transferring energy from PV to battery is most efficient when staying on DC instead of first inverting to AC and then back to DC again.
The question is: do you really need that higher efficiency ?
In summer you have excess solar energy so even without the higher efficiency you probably won’t have enough battery capacity to store it all.
Only in winter time (when efficiency matters) you’ll notice some energy loss in the double conversion DC-AC-DC, but only on days where you have enough solar to charge your batteries.
When directly consuming your solar energy (by AC devices), efficiency is highest when the least conversions are being done - thus when solar is turned into AC by the Fronius inverters.
Two extra 250-100’s and a 150-35 will set you back ~€1500, for a 10% increase in efficiency during a few winter months.
Unless this can save you ~€150/year on electricity pulled from the grid (during winter), my gut tells me it’s not a good investment and you can probably save more by switching to a different energy contract
.
i got 6 bluesolars under my 3 multiplusses
MultiPlus II 48 GX will be opened too…
