There is no formal requirement for a 30 mnute backup battery other than the UF CSSALT specifications, which are reasonable and even minimum in this respect to allow a patient to be moved from one location to another.
Enclosed is a draft battery life test protocol and the successful results of a battery test performed on April 8 2020 demonstrating the system easily runs at least 60 minutes.
Took a total of 4 hours to perform and document all of this.??
Gordon Gibby