Alan,
I think you will find this is hidden within the RF module. but even the manufacturer's description is confusing.
Yes, the RF module's description is confusing. I couldn't ascertain whether pin 22 (Vbatt) would source current to charge the battery or not. By measuring the battery voltage in my unit (it indicated discharged), I decided it was not sourcing current; it's only an input. Apparently there is no "automatically" :-(
73,
Joe, K7JD
