Luis - in the US it is an accepted number that the cost to recharge a battery of $2.85 to $3.00 per charge and it can be safely assumed that one battery charge (battery discharged to 20%) will provide the same amount of run time as one 33# LPG tank. Of couse these numbers are based on batteries/charges are in could condtion, properly matched, proper tires are installed on the electric (electric compound tire - most are today but there are still a few makes that aren't).

Hope that helps.