The voltage output of the charger must meet the voltage requirements of the lithium battery pack to ensure safe and efficient charging. Using a charger with incorrect voltage output will result in overcharging or undercharging, which may damage the battery and shorten its life.
If lithium batteries have been deeply discharged they should be charged at a very low rate until they reach their minimum voltage above which they can accept the usualy high currents. So this sounds like a protection feature to me to prevent damage. ... but your batteries should never be seeing a low voltage disconnect event!
On the other hand, undercharging can cause irreversible capacity loss, negatively impacting battery performance and life. Discharging below the minimum voltage threshold of a lithium battery must be avoided to keep the battery healthy and ensure optimal functionality. Using a certified charger to charge lithium battery packs must be considered.
Improper charging might result in the complete loss of battery capacity or even death. The charging device will measure the no-load cell potential at the start of a normal recharging cycle. If this value is less than 2.5 V, the cell is in a deep discharge state and will require a 'prequalification' charging period.
Lithium-ion or Li-ion batteries power nearly every facet of our lives. They’re famous for their high energy density, which lets them run for extended periods before needing a recharge. That said, you also need to know about charging lithium-ion batteries safely.
Li-Ion batteries are readily damaged by charging at too high a voltage. Internal gassing, overheating, and finally exploding might occur if the charging voltage is pushed over its optimal value of 4.1 V or 4.2 V. Even a 1% rise in voltage over this ideal level could induce the lithium ions in the cell to start converting to metallic lithium.