Battery-Powered Ceramic Pet Water Fountain with Sensor, 101 fl oz

This battery-powered fountain holds 3 liters (about 101 fl oz) of water in a round tank, so a cat or a small dog has fresh, moving water without a cord running across the floor. A smart sensor on the top unit controls the pump, and water passes through a layered filter before it reaches the bowl.

Four models share the same tank. The Basic model has a 2500 mAh battery. The UVC Sterilization, Heating and Heated UVC models use a 5000 mAh battery, and the heated versions add a warming element for cold rooms. Each comes in black or white, and each includes a starter set of filter cartridges.

Filter cartridges are meant to be changed about once a month, and a 12-pack is available as its own option, so it is worth adding one if you want a year of spares on hand. The cartridges are sold in the picker next to the fountains.

The tank is one size across all models, so the choice comes down to battery size and whether you want heating or UVC. Because it runs on a battery, it needs recharging or battery care between uses, and the larger-battery models cost more.