Powerbanks ?

[Waterworks178]

What is the maximum capacity of battery of any type as in a powerbank or powerstation that can be charged in one hour from a 13 amp / 240 v socket ?

 

[Bluejets]

Battery recharge current is a factor of battery size and type.
Too many factors for any open ended answer.
Regardless to say it has next to nothing to do with the power outlet in your house or wherever.

 

[Harald Kapp]

Regardless to say it has next to nothing to do with the power outlet in your house or wherever.

At least the mains available gives an upper limit: [imath]13 A × 240 V × 1h × 0.9 = 2800 Wh[/imath], assuming a charger with an efficiency of 90 %.
More likely only 2500 Wh with an 80 % efficient charger.

I think the "powerbank" in question here is not the classic 5 V USB powerbank but somethink more beefy (example).