Testing and maintenance is very important with any emergency equipment. Whether it is monthly or quarterly your satellite phones need to be charged up. Even though a lithium battery will stay charged for months if it is allowed to be discharged for an extended period it could damage the battery to the point it cannot be recharged.
Periodic testing is important. It keeps you familiar with the satellite phones and their functions in the event of a disruption of conventional communication. It also insures the phones are active with service. If someone in the organization fails to pay the service billing, the phone could be deactivated without the knowledge of the person in charge of emergency communication.
It is important to have a simple guide for each user in the communication group and at least annual training on the basic usage of the satellite phone. Having a working satellite phone but not knowing how to use it makes it worthless. During hurricane Katrina many people could not use their satellite phone because they were not trained on the usage and/or did not follow simple instructions.
Satellite phones are not like cellular phones, you cannot just turn them on and start dialing. With a handheld satellite phone without an outside antenna you must be outside away from tall structures and trees to obtain line-of-site to the satellite providing the phone service. You must allow the phone to register with the satellite before dialing which can take a few moments. In the case of Iridium dialing patterns are very different from the standard North American dialing everyone is use to with their cellular phone.
It is important to test and maintain the phones and the users must be familiar with the equipment because during a disaster it can be chaotic with little time for testing and training.