SunnyBoy inverter

OK I'm late to the party in terms of finding a battery solution... so can anyone give me a brief synopsis of what options I have for getting a GivEnergy battery retro-fitted to my current PV setup?
20 panels (4Kwh?) on south facing roof
SunnyBoy inverter installed in garage
Both working consistently -- installed Sept 2011.

I fear that the age of the inverter might count against me, whether or not SB is compatible with GivEnergy (or vice-versa). Just looking for a general view on what my options are. On the plus side I'm on a generous FIT so I'm keen to hang on to that (looking at other discussions on this forum) but I have recouped the original capital invested and now I'm looking at the next stage(s).

dont change the sunnyboy as you might mess up your FIT contract. fit a AC3 INVERTER and battery's of your choice if you can get them , my solar is like your's eleven years old and a sunnyboy 4000TL still working just fine , you will find instantly once fitted you energy consumption will drop dramatically with 9.5kw of storage.The only set back is vat @ 20% as an add on but zero vat on any : new solar install... that is just not fair

JohnDawson If your FIT equipment becomes faulty, it can be replaced with new but you can't change the installation (ie add a battery to the inverter). If your FIT is due to run for many more years then AC3 is the way to go unless you've another roof crying out for PV.

My Sunny Boy SB3300 inverter was installed in 2009 and is working fine with the GivEnergy AC3.0 inverter. Way to go if you don't want to lose your FIT payments.

I agree Sunnyboy running since 2011 with 3KW had AC givenergy inverter installed with 8.2 battery last year working very well leave existing if it ain't broke ......