Generally, the more expensive the light, the lower the parasitic drain will be for its electronic switch. But the parasitic drain can vary widely. I have measured some of my lights with as little as 2 microamps of drain, and others with over 1 milliamp.
Most Zebralights are among the lowest drain, and you can essentially ignore the drain completely. It’s lower than the self-discharge of batteries, and would take over 20 years to drain a battery.
Some of my cheaper lights have a parasitic drain that depletes them in just 2 months. This makes them essentially useless for storage with batteries in them.
If you’re storing a light for long periods of time for emergencies, then get one with a mechanical tail switch. That way, it will have zero drain.
