That's not the correct model of battery for the FZS600. It won't fit the compartment.It should be a YT12B-BS.This subject came up before on here....http://foc-u.co.uk/index.php/topic,15269.msg173441.html#msg173441
Quick heads up: they've got the Yuasa YTX12B-BS going for £30, perfect for FZS600. Not a bad price if you need a new bat for winter.http://amzn.to/2f6grLM