the etha noid needs and wants a name brand fresh battery to make it click when its not gassed up, when its gassed up the air assists the opening and does not require as much battery power................ there for if it aint broke dont f**k with it
Yes it is perfectly normal. The solenoid works off a combination of electromagnetic drive and air assist (once gassed).
With a most of the solenoids, if you have a brand new battery that is a decent brand you will get the solenoid to click every time as the charge being supplied by the fresh battery is enough to drive the internal mechanism on its own. However, as the battery level drops even slightly, when there is no "air assist" in the solenoid the battery cannot fully drive the mechanism every time you pull the trigger. However once the air is on the gun the air assist and the battery combine to make sure the solenoid funtions perfectly.