Solar panels selector switch

[Sergio Veltri]

Hi guys,

Is there such a thing as a solar panel selector switch?

I have more solar panels than my current 5 Kwh battery pack can handle. Say that in a normal day 4 panels are ok but in a cloudy day I might want to add more panels to send to the SBMS120 I have. Or maybe I want to play with heating water and need to divert 4 panels to that project. Or when I buy more batteries I need to divert more panels to it.

What can I use to be flexible and add or remove panels as I need?  Imagine 20 or 30 panels and 3 projects that can use them (SMBS120, Water heating, water pump for instance)

Any guidance would be much appreciated.

Thanks

Sergio

[Dacian Todea]

Sergio,

On the SBMS0 there is an option dual PV array where up to 3x larger array than battery can handle can be added.

The way that works is that SBMS0 will monitor the PV current and there is a set limit and the PV array is split in two parts 1x and 2x and so when it is sunny just the 1x array is connected then if amount of sunlight drops to half the 2x array is connected and if amount of sun is lower than 2 thirds then all panels are connected. While some of the panels are not connected they can be redirected to heating or some other similar application.

Tho this is not working with SBMS40/SBMS120 since those have build in PV charging controlled directly by ISL94203 instead of being controlled by micro-controller as on SBMS0.

The DMPPT450 was also a device that I no longer offer that did the same thing selecting a number of panels based on amount of light to be diverted to battery charging.

You can build something it will just need to be fast enough in order not to trigger the over-current protection on the SBMS120.

But a 200Ah battery you will want to charge with max around 40 maybe 50A so say 4 panels then you can add two SSR one for 4 panels and one for 8 panels and use the EXT IOx as type 1 (4 panels) and type 6 (8 panels) to achieve same thing as SBMS0.  

[Bernd]

Hi Sergio,

check the DSSR20 (and soon DSSR50) WITH diversion. it will switch solar power between a full battery towards a e.g. water heating element.

Also check the SBMS0 dual pv array option. It will allow to set a charging limit for your battery and the sbms0 will switch between 3 levels:

-level 1 - small array with e.g. 1/3 of your solar power

-level 2 - your bigger array with the rest 2/3 of your solar power

-level 3 - both arrays with 100% of your solar power.

You could set a charging limit of e.g. 100A for a 24V battery and have 

a level 1 array with 2,5kwp of solar (which should give you up to 100A in full sun under ideal conditions).

a level 2 array with 5kwp of solar

In cloudy conditions the system will use all panels and under full sun only the small level 1 array...

Dacian was fast in replying to your post, so take care of his comment and ignore mine (I´m only beginner level :-))

All the best and big thank you to Dacian

Bernd

[Sergio Veltri]

Thanks Dacian and Bernd! 

Are the SSRs available? I will be in the States in Jan/Feb so it might be easy to get them shipped. Please let me know and thanks again!