what ever you do DONT buy britpart-presoilte there absolute garbage mine last 13 months and have searched online to see if it was a one off and people have reported getting a few days out of new ones. Personaly i buy used genuine ones got 2 last week for 16 and 20 pound delivered, as i use it off road i cant justify 100+ for a good bosch one, also i carry a used spare as you cant push start an auto. BTW Bosch seem to be the best.
Cheers Andrew