Shallow and deep discharges are not as good because they cause the battery to spend more time in the "danger zone" of full or zero. Notice the 50% figure resul

Shallow and deep discharges are not as good because they cause the battery to spend more time in the "danger zone" of full or zero. Notice the 50% figure results in 750 full-charge equivalent cycles. Also, these figures are general and the magnitude varies based on the exact battery type.