I have a 2600mah lithium ion battery (with regulator but I check voltage before the regulator) and want to know what's the minimum voltage I can go down to with a 1amp load while at the field to safely fly. I have a dig voltmeter with .5, 1 and 2 amp load settings and check with 1amp as I don't think my servos will use more than that on average, especially the way I fly, very little throttle management, very little rudder, mostly aileron, then elevator.

I was told by one fella that 6.6 volts would be the absolute minimum so I put a label on my plane "6.6v min" to remind me.

Yesterday, while flying, another guy says, what's that mean? I said that's my minimum voltage to fly at. He says, 'NO WAY! You shouldn't go any lower than 7volts with a 1amp load!" I pointed out without a load I was up to 7.7V and with a .5 amp load I was over 7.1V. But at 1amp, I was reading just about 6.8V and with a 2amp load I was at 6.4, and he said it wasn't safe to fly, so I stopped flying for the day.

What amp rate should I use and what's the lowest voltage I should fly at safely at that amperage? The servos are five JR DS821 and a single small servo for throttle.