The (quality OE Varta) battery in my C5 V6 has finally given up the ghost after 8 years of service - well not given up but the starter seems more sluggish than usual. I ordered a Bosch S4 to replace it, just tackled the job expecting to run out of light - 5 minutes later the car was spinning over like a dream - I was amazed to discover that battery replacement is tool-free! Well I never! What a nice surprise - who said Citroëns are always a pain to work on? :-)