Grid tied inverter and Classic in parallel?

[Hybrid]

Hello, my first post!
I have connected a SMA SB30TL-20 inverter to my panels. May I run a Classic 250 in parallel on the output of the panels to charge directly a battery for off grid applications? Is there a sufficient potential separation of the Classic input and output? How will the two MPPT interact with each other? Till now I use a Siemens SITOP DC-DC converter with a very wide input.
Regards     

[boB]

Hello Hybrid !  Welcome !

No, I would not connect anything in parallel with the Classic's input.

This may possibly hurt things.   Thank you very much for asking first !

Isn't that SMA unit higher voltage than even a Classic 250 would allow ?

boB

[Hybrid]

Hello boB,
I designed my system with strings of 220V VOC at the very low end of the inverters range in order to use some equipment during the day in direct connection with the panels e.g. MEGAMAN classic LED-Bulbs, heaters and units with wide universal voltage input. The losses compared with 350V VOC design seem to be less than one percent or so. But I can use even minimal power when the inverter doesn't start because the panel is covered by snow or in the dawn when the performence of the inverter is weak. I have to separate the inverter from the panels in such extrem situations manualy or with an automated light level switch because it takes then up to 20W without functioning. My emergency system uses simple SITOP DC-DC converters from Siemens to get usable 24 Volts and for an offgrid inverter!