never forgets but quickly discharges

I started using these as night-time bathroom-finding-aid lights just in time to be impressed that they could stay bright enough all night to allow children to avoid plummeting down the stupid wee set of three stairs between the landing and the bathroom. A few weeks later and they can still just about be perceived to still be on in the morning but I only if they've caught a couple of hours direct sunlight on a windowsill.