I have a 16 V lithium battery with 60 Ah.
How much energy can this battery store?
My home specifications are: 220 V mains and I have a contracted power of 6.9 kVA.
The battery is 60Ah at 16V
So therefore it can provide 60A at 16V for a period of 1 Hour
Alternatively it can provide 30A at 16V for a period of 2 hours
Or 15A for 4 hours - you get the drift. It's the number of amps it can provide in total when drained flat over a period of one hour. The slower you drain it the less current you use, the longer it lasts.
So, for 1 hour it's 60A.
If P=VI then P=16*60
That's 960W over the period of 1 hour.
So 0.96KWh. The length of time this will be for depends on the current you draw.
Your mains power supply has nothing to do with it.
The energy available from your battery is 16 V x 60 Ah = 960 Wh.
Your home 220 V isn't directly relevant to the battery.