I want to create a conditional formula that adds a specific value...

I have an E-Z pass for going through toll booths where I live. I like to keep track of how much the tolls are costing me each month on an excel spreadsheet. I have a cell set up that lets me know the total amount left on my E-Z pass balance by subtracting the sum of the amount I have spent from my initial E-Z pass balance. For my situation, my original balance was $35. So my formula for that "total" cell is very simple...it is just 35-sum.

My issue is that when my E-Z pass balance reaches $10 or less, it automatically recharges for $35. So I would like my excel spreadsheet to realize that my balance has reached <=10 and I want 35 added to that so that my E-Z pass balance is accurately reflected on my spreadhsheet. What formula would allow me to do this?