What is a safe discharge level?
Again a difficult question. There is no safe discharge level. Batteries are consumables. Every battery has a finite life. Each discharge and recharge cycle uses up some of it’s life. The deeper it is discharged, the more it shortens the battery’s life. An accepted best compromise is to discharge to 50%. This is known as the 50% rule. The reasons for it are quite involved but it is a well accepted and well calculated figure. It works. Stick to it. Occasionally discharging deeper than this is fine. Just don’t over do it. The usual trick of running lights until they go orange, then recharging the batteries is one of the main causes of premature battery death. The other main cause is not recharging fully.
