External to Internal Powering with 7-Series Recorders
7-Series recorders automatically switch from external DC power to the attached Li-ion battery when the external voltage falls below a 9 volt threshold (or the setup-menu set voltage on the 788T). This seamless switchover provides protection against sudden or unexpected loss of external power.
External Low Battery Voltage Reference
Because the 7-Series recorders can be powered from external voltages from 10 to 18 volts, the low battery warning level is user-selectable over this range, from 10 to 18 volts in 0.1 volt increments. Set the low battery warning level in the Setup Menu option Power: Ext Low Batt Volt.
External DC Low Voltage Warning
When the low voltage threshold is reached, the recorder will alert the user with:
- Warning bells in the headphone monitor
- Flashing green Power LED
- Flashing battery indicator on the LCD display
External Powering Recommendations
- Use external DC supplies capable of providing at least 15 watts (up to 40 watts if battery charging is occurring on the 788T), with a consistent voltage drop as capacity decreases.
- Power supplies using NiCad or alkaline battery chemistries are not recommended for use as external DC power sources for 7-Series recorders. These chemistries have a "memory effect" which prevents the recorder from reliably switching over to the internal battery, potentially shutting down the unit.