ISDT 608AC Discharging

Hello, i have this charger: ISDT 608AC and i would like to test salvaged 18650 battery.
And here is the problem, minimum voltage i can discharge to is 3.1V
So i can't test battery properly.
Is there any way to change this?

Discharging to 2.5V cutoff instead of 3.1V cutoff might net you another 5% of capacity. So divide your recorded capacity with the 3.1V cutoff by 0.95 to estimate capacity. But you really shouldn't be going that low in practice for best cell life. Take a look at typical lithium ion discharge curves for reference.

Thank you for claryfying it to me.
If it's only 5 % i won't even bother.