Telit FAQs, Part 13: What is the best type of battery to use with my xE910 module?
In the xE910 HW specification, it is said that the maximum voltage allowed is 4.2V (Normal Operating voltage range). Some of the latest Li-on batteries, when fully charged will rise to 4.5V (Extended Operating voltage range). Will there be a problem?
Note: This explanation is for the case where the battery is directly connected to the cellular module, with no power conditioning circuitry. If you are using a power conditioning circuit you can use whichever battery you would like, as long as your circuit is able to provide the needed voltage and max current specs required by the module.
The module is best supplied by a 3.7V Li-Ion battery type when directly connected to the module since the 4.2V operating voltage can be met with this battery type.
The three cell Ni/Cd or Ni/MH 3.6V nominal battery types or 4V Pb(Lead) types must not be used since when directly connecting to the module the 4.2V range could be exceeded when the module is operating.
The module has an extended voltage tolerance of 4.5V however the module is not intended to operate at this voltage, only survive it.