The project operating at nominal 3.3V will almost certainly operate just fine at 3.7V. Check the datasheets for the ICs used.
However, you will need to disconnect the battery from the circuit (at least the Vcc line) to charge it.
The project operating at nominal 3.3V will almost certainly operate just fine at 3.7V. Check the datasheets for the ICs used.
However, you will need to disconnect the battery from the circuit (at least the Vcc line) to charge it.