Thats why the cover letter is quite important to explain clearly and concisely all the details.
Basically your just proving your Company ie you and your mahal will be self sufficent.
So like many others I just made abasic spreadsheet show my outgoings and ingoings at present, i even showed what they would be when the Wife was in the Country. Ie Council tax at full rate, double the food spend, electric far higher etc. Showed all costs for moving over and settling in I looked at it as look I have thought about this and yes look I have far more than you are looking for as a bare minimum.
Like others say and you do, no normal person leaves money in a current account just what they need and now particulary with internet banking and transfers in seconds every little bit of intrest can be gained.
Just show you have more than enough funds which you can access easily and your be fine.
