Directly below is the overview of a project that has been working well for around three months.
A 6 Watt, 12V LED spotlight powered by a 12V 7Ah sealed lead acid battery, controlled by a timer switch that runs the light for 10 hours a day. The battery is charged by a 12V 50 Watt solar panel with a solar charge controller between the panel and the battery.
The problem that started occurring a little after three months is that the battery will no longer run the light for the full 10 hours. When the battery was fresh from the store, I had timed how long the battery could run the light straight, and it was close to 13 and half hours. When I was doing the math for how much battery I needed to run the light for 10 hours, I did not take into consideration that lead acid batteries do not like being fully discharged on a daily basis. I believe I have ruled out the solar charging as a suspect by charging the battery on a battery charger with the same outcome.
Is there a particular type of battery that would be better suited for this type of usage or would my best option be to get a sealed lead acid battery that can handle 10 hours while only being discharged 50/60/70 percent?