i'm trying to find out what start power i need for a battery.

i've had a look on here but can't find an ans. The battery i had on the car had a start power of 600 so i replaced it with the same (bosch) this battery has only lasted since july.

Try Varta works pretty well on mine m8:o:o

Bosch is a good make and should be suitable for your car. I have a Bosch battery which is now some 3 years old and recently left my headlamps on for some 3 hours when parked. It still started first pull. I would suggest that you get your charging output / circuit checked to ensure that enough is being put back in when running under load. Also have you had the battery tested to confirm that its duff, if so I would still take it back to your place of purchase as it does not look good for Bosch. It could be a faulty battery due to a manufacturing failure.

Hey mate I took the car to halfrauds and they stuck in the biggest one that would fit and its been in sincve june and stood since august and it work fine.