Do AGM or GEL batteries have a “memory” like ni-cad batteries?

One of the significant disadvantages of nickel-cadmium (ni-cad) batteries is that after shallow discharge cycles, the unused portions of the electrodes “remember” the previous cycles and cannot sustain the required discharge beyond the depth of the previous cycles. The capacity is lost and can only be restored by slowly discharging and charging the batteries completely through costly and time-consuming maintenance periods that require the batteries to be pulled from service (generally, outside the application). VRLA DRY CELL AGM or GEL batteries do not exhibit this “use it” or “lose it” capacity-robbing effect known as memory.

It is important to note, however, that if any lead-acid battery is left unattended and discharged for extended periods of time, its ability to do its job will be diminished and eventually extinguished.