There isn't much here other than the AFM procedure. I'll give this more thought when I get a chance.
Everything here is from the references shown below, with a few comments in an alternate color.
IMMEDIATE LANDING IS REQUIRED WHEN ANY ELECTRICAL CONDITION REQUIRES OPERATION ON MAIN BATTERIES, EBHA AND UPS BATTERIES ONLY (RAT UNAVAILABLE).
Fully charged main batteries will provide approximately 10 minutes of electrical power after two APU start attempts. The EBHA and UPS batteries will provide approximately 30 minutes of electrical power.
A MAXIMUM OF TWO, 30-SECOND APU START ATTEMPTS MAY BE PERFORMED WITHIN THE APU START ENVELOPE (37,000 FEET OR LOWER).
AS MAIN BATTERY VOLTAGE DECREASES, OPERATION OF VHF 1 MAY DEGRADE. TURNING ON BKUP VOLUME WILL ALLOW CONTINUED OPERATION OF VHF 1 AND ALLOW COPILOT TO LISTEN TO VHF 1 COMM TRAFFIC.
DU1 and DU4 are powered by the main airplane batteries. Consideration should be given to securing power to one or both DUs (DU1 POP B4, DU4 CPOP B2) if the situation permits, both SFDs will be powered. IRS 1 will be powered by the main airplane batteries; however, IRS 2 and IRS 3 will automatically revert to emergency battery power. Unless required by operational circumstances, it is recommended that IRS 2 and IRS 3 be selected OFF to preserve EMERGENCY POWER resources.
THRUST REVERSERS WILL NOT BE AVAILABLE.
Gulfstream GVII-G500 Airplane Flight Manual, Revision 4, August 29, 2019
Gulfstream GVII-G500 Production Aircraft Systems, Revision 3, July 15, 2019
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