Hi Ashleigh! Thank you for your feedback. To clarify, our Meke Milk Warmer should be lasting you around 4 - 6 warming cycles on a full charge with average use. 200mls and 45 degrees is almost our maximum capacity and maximum temperate. Generally speaking, this would be considered above average use, which means your battery will drain faster as the warmer is taking longer to heat up such volume of liquid. We would love to discuss this further with you to ensure you are happy with your warmer. Please reach out to us with your order number and details on your usage so we can better assist you 🙂