2-3kW PV setup advice / ideas.

[shakalnokturn]

I have some equipment as it is but I'm seeking ideas from wiser people here as I do not know of half the equipment that exists.

I'd like a setup that can:

MPPT at all times.
Grid-tie only to not waste any excessive PV production.
Run disconnected from the grid if needed.
If possible switch automatically from grid-tied to standalone without blowing-up.
Charge batteries. (48V)
Run off batteries if needed.

Things I have:
(Sorry some datasheets are French but the specs should be clear enough.)

3kW non-isolated grid-tie inverter.
http://ecosun.fastsite.fr/images/ecosun/upload/fiche_technique_Ainel_K_v2.pdf

Ten 280W polycrystalline PV panels.
http://recom-sillia.com/downloads/datasheets_en/RECOM-SILLIA-60P_265-285_(Plus)_EN.pdf

Three (only) second hand Marathon L12V80 12V 80Ah batteries.
https://www.blueboxbatteries.co.uk/dyn/filemanager/exide-marathon-l12v80-by-blue-box.pdf

[fourtytwo42]

Well first of all if you want a battery based system you do NOT want a transformerless GTI or else your battery bank will be at grid potential, highly dangerious!
It seems your best bet is a charge controller to connect your panels to your batteries though I have not seen one that powerful and then a low voltage input ISOLATED grid tie (that also has an inverter mode and a transfer switch) to connect your batteries to the grid.
You mention a 48V battery bank and then seem to say you have 3 X 12V batteries ?

[mtdoc]

To do what you want you will need a "grid interactive" inverter.

For example these Outback Power inverters

Outback used to sell inverters compatible with the European market - not sure if that is still the case.

German company SMA makes the Sunny Island inverter

I think Victron (Dutch company?) also makes some grid interactive models.

For an MPPT charge controller - I can highly recommend the Midnite Solar Classic 150 inverter for your application.