What is the electrical load?
The standard Nature's Head separating composting toilet uses a small 12 V ventilation fan. The electrical data, PDF page 14 / printed 12, gives 0.07 A, equivalent to 1.68 Ah per day with continuous operation. The catalog treats the fan as always on. The mixing handle is manual and adds no electrical demand.
That page also prints an instantaneous wattage inconsistent with its current and daily energy figures. The catalog retains the stated 0.07 A and does not copy that wattage typo into the power data. At 12 V, 0.07 A would be 0.84 W by calculation.