Battery providing more power than required

Hello, I’ve noticed recently that my batteries (2 x 9.5kw) seem to be over providing wattage. For example if consumption is say 200 watts the batteries discharge at around 250w to provide the 200w without any grid export. It’s usually around 20% - 25% higher than needed which drains the batteries faster than necessary. If the batteries are empty then the grid provides exactly the wattage required (ie 200w in this example). Not sure if this is normal? Thank you

Inverter (in)efficiency losses converting DC back to AC will be a good portion of the loss. If you look at inverter output rather than battery output the figure will be closer to consumption.

Thank you, that makes sense. I guess it’s less efficient when it’s colder as my kit is in an unheated workshop.