Instruct: Classify a given Amazon review as either positive or negative.
Query: Good replacement battery for 1DsMKII

I've used the Canon batteries and they are over-priced. I've used other second party replacement batteries and most of them do fine in normal conditions but seem to falter in cold weather. This is the first replacement battery I've used in my 1DsMKII that held up as well as a Canon OEM battery in cold weather. Everything on this battery works identical to the Canon version and I can recommend purchasing this model for your camera. No complaints and the price is very reasonable.