What does the "Hour", "Standby Use" and "Cycle Use" specs for a SLA battery mean

[ledtester]

Attached is a pic of a SLA battery.

What does the "20 Hour" refer to?

And what do the "Standby Use" and "Cycle Use" voltages and current specs mean?

[tautech]

20hrs WRT the rated AH is the discharge time.

Standby charge voltage lists the max voltage for continuous charge. eg alarm backup etc.
Cyclic is for portable use where the battery is NOT on continuous charge and only topped up from time to time. eg hunting spotlight.

[ledtester]

How do the 9AH and 20 hours relate to each other?

Doesn't 9AH mean the battery will last 9 hours if I draw 1 amp continuously, or 18 hours if I draw 0.5 amps, etc.? How does the 20 HR figure in?

[ovnr]

9 Ah is capacity; yes, that would normally mean that an 1A load would deplete it in 9 hours, etc. However, due to lead acid batteries being somewhat terrible, the usable capacity gets worse with higher loads. If you put a 1A load on it, it might only have 8Ah capacity; if you put a 10A load on it, it might drop to 6 Ah.

In this case, if you spend 20 hours discharging it, it will have a 9 Ah capacity. You could also write that as "With a 0.45A load, the battery will have a 9Ah capacity".