Just guessing but I would think nothing below 11.3V
No use guessing Bob
The voltage has the be 10V to trip most starting solenoids and 9V or better to trip the fuel solenoid
But numbers are for politicans to lie about & accountants to manipulate to justify their bonuses
This is why I always advise to bypass using jumper cables and forget about getting the right numbers.
In the work shop I have a dedicated continuity meter that buzzes loudly and a test lamp with the thin probe insulated for most of it's length .
These are quicker and give better results.
The test lamp has a H4 globe in it soit pulls power.
Way too many hours wasted becaue a meter showed continuity but the circuit failed when ever you try to pull a few amps through it.