question

tore avatar image
tore asked

Is ther a better use of solar power in an offgrid system

I am struggling with the correct settings of my solar offgrid system.


System setup:-Multiplus II 48/3000/35, Smartsolar 150/35, Color Control GX (DVCC enabled - charge current limit at 35A, STS, SCS and SVS enabled), BMV-720, 6x320W solar panels, 48V/7000Wh Li-ion battery.


Float is set to 54V and Absorptium is 56,8V (standard settings for Li-ion). When battery is charging, then solar is used for direct consumption an the rest is used for charging. But when the battery is fully charged, MPPT goes in to Float state and the solar current is 0 and all consumption comes from the battry. The next morning a new cycle is started (Bulk-Absorptium-Float). During the summer the solar power is higher than my consumption so it is not a problem, but during autumn/winter it will be.

Is this normal or what can I do to maximise use of the solar panels?

beskjært2.png

screenshot-20210614-142048.jpg

offgridVEConfigure 3
beskjært2.png (42.9 KiB)
screenshot-20210614-142048.jpg (278.4 KiB)
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

2 Answers
klim8skeptic avatar image
klim8skeptic answered ·

What pics you have posted look perfectly normal.. For a charger transitioning between absorp and float stage.

3 comments
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

tore avatar image tore commented ·

Float is at 54V the battery will probably have a SOC at maybe 50% before the MPPT starts to deliver power for direct use. Is it possible to make the MPPT deliver power for direct use before i reaches 54V?

0 Likes 0 ·
rslifkin avatar image rslifkin tore commented ·
The float voltage will have to be at least slightly above the battery resting voltage for the MPPT to deliver power to loads. If it's not, it won't see any demand for power until the battery voltage is pulled below the float voltage setting.
0 Likes 0 ·
tore avatar image tore rslifkin commented ·
Yes I understand that but I think that is not the ideal solution. I want the MPPT to deliver to direct to load whwn the battery is fully charged. If I want to charge my electric car with the excess enegy it wont be possible as it is now
0 Likes 0 ·
Jason Bolduc avatar image
Jason Bolduc answered ·

Per the previous answer it appears that your system is operating as designed.

Use of excess power during the summer is often used to heat hot water....

.... however in the next few years you will begin to see the adoption of hydrogen fuel storage in the summer for use in the winter - very exciting times!


2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Related Resources

Victron Offgrid page

Additional resources still need to be added for this topic