Consumables supplied with product.

This is just research if I buy a product that comes with consumables say a camping torch that came with batteries. now I use the batteries in the torch and then replace them after a month then the torch develops a fault within six months of me purchasing it, must I return the torch with the original batteries in order for the seller to replace or repair the product. I'm writing an essay on consumer writes in th UK within the next few days so any fast reply would be very well appreciated. Oh and does the condition of the original packaging matter. (I doubt it does but the more info the merrier!)