A fully charged battery will store longer than a drained battery. A trickle charger will keep it at full charge even when not in use. Is this perhaps the purpose of daily prayer for protection or other needs, to keep that protection energy available on an ongoing basis, and not lose potency over time?

This again is a good analogy to help people understand that prayers are not static, they are an energy that persists but energy wants to go somewhere. It wants to flow into action and it can dissipate, or be drained away, or be canceled depending on the actions of the originator. It will be connected to you and will depend on you for continued relevance. This is always taken into consideration, so if you want something to happen even beyond your demise, it is of special value to make that clear in your intention. The power you have in your thoughts, and especially your feelings, will animate the prayer with a powerful intention. If it is heartfelt in particular, it will be on Creator’s wavelength and given the greatest potential answer because it will be using the frequency of love that answers all prayers. And this speaks to the virtue of living your life in divine alignment, which will mean holding a vibration of loving kindness in your thoughts and in your heart as much of the time as you can. This becomes natural and effortless when a state of divine alignment is reached and people attain that stature, and becomes easier because the person becomes invulnerable and will not be thrown out of balance by adversity. They will simply take it in stride and find a way to overcome it without losing faith, without losing confidence in themselves, and without succumbing to fear and doubt. Holding that vibration of loving kindness is analogous to having a trickle charger that keeps you topped off with energy, having a full tank, plenty to work with, and never being caught shorthanded, with an answer, with a solution, with a plan that you can devise that will bring about the righting of a wrong, the restoration of balance, and allow you to get back on track quickly and easily, and when you are in the groove, it will be very rare that something knocks you off your stride. You can hum along and have a life of joy and calm, even tackling heavy duties and responsibilities. You get your life force energy from the divine. What you do with that energy will determine how you feel in any given moment and what the energy might be you have to work with. If you have closed down that lifeline, you may feel tired and depleted. If you are in the flow and have that throttle open wide, you will accomplish much more and have much more to give because you are allowing it in and not diminishing yourself in some way. That state of being can be cultivated through a divine partnership and you can use prayer requests to make it so.