1998 Polo and only 20K on the clock
lives in garage when not used
1st battery lasted 8 years
2nd battery from Halfords died May 2009
3rd Battery heavy Duty Calcium Battery Halfords May 2009 has died 3 times if left for just a week ...........trickle charged and worked each time after......... till left for a week

Returned battery under 4 yr guarantee ........got a refund after argument
they tested it and claimed it had 10Volts and warped cell

Claimed must be something wrong with the car

Only problem i have is drivers side door lock barrel has broken .........the solenoid must be OK as can use central locking by depressing drivers door knob from rear passenger door and then unlock from passenger door side

Where do I start looking for problems if they even exist