It depends on the type of battery in your pushcart, but there are some minimum metrics that we would like to see before settling on an electronic pushcart. Lithium batteries will usually have a range that will get you at least 2 rounds out of a single charge. Acid-based batteries, while far heavier, can last a long time, too.
Each battery type will be different, and you will also see a difference in performance from 12V to 24V options.