I've always kept old/obsolete doodads like timers so I just use an old mechanical style with the "clock" dial. One advantage is if the power blips, the timer is just offset by the outage time and still gives me 1 hour per day.
Many of the fancy digital ones just stay off and blink "12:00" like VCRs.
With Li ion batteries you get the longest lifespan if you only charge to 80% and discharge to no less than 20%
The best chargers will do this for you, but then you probably have to upgrade them to get that feature ($$)