Voltage Regulator Max 3.8v, Lipo cell ok?
If you use a smart charger such as the imax 1010b+ you can set it to charge your lipo battery to 4.1 volts or less instead of the usual 4.2 volts.

Your lipo battery would have a longer lifespan if charged to only 4.0 volts (i.e. more charge/discharge cycles) and you won't lose a lot of capacity from the lower starting voltage.