Greetings, I am just starting to get aquainted with my new Sony DSC F828. I am looking to buy a couple of spare batteries and note a great disparity in price and an interesting difference in specs. The camera uses the NP FM50 battery with a designation of 1200mAh. I have seen less expensive third party replacements with the designation of 1800 mAh. Could someone sort this out for me and tell me if this is a good thing or a bad thing? Many thanks.