The radio modem enclosed in the SATEL-321 can be switched ON or OFF using either the SATEL-321 push buttons or through the 12-pin data connector. The model 3ASd can also be configurated with the programming push buttons in the casing.
Boot charging of the battery to full capacity takes 3 hours, to 90% level only 1 hour. Operation of the modem is possible also during charging. The SATEL-321 batteries can be charged from whatever power supply that provides 11 ... 30 Vdc voltage and minimum 60 W output power. Available from SATEL there are a mainspowered charger that operates at 100 ... 240 Vac, and a charging cable for use in vehicles with 12 or 24 Vac power systems. When charging the batteries, the ambient temperature has to be between +5 ... +40 °C.
The operating time of the modem (typically 8 - 10 hours) facilitates even more time-consuming field jobs without recharging. The SATEL-321 casing has indicator lights for Power On (green), Charging (yellow) and Battery Low (red). Low battery charge level is also indicated by an audio signal. SATEL-321 comprises an adaptive capacity meter, for monitoring the battery condition. The user can see at any time the prevailing charge level of the battery, provided the display model 3ASd is used.