The specification "7 Ah / 20 hours" states that the battery capacity, multiplied by the hour, is 7 Ah. However, there is a catch - the useful capacity of a lead-acid battery depends on the discharge rate, and the "20 H" part specifies that the 7 Ah portion only applies when the capacity is measured over a 20-hour period.
In other words: If you connect the battery to a load that draws 7/20 = 0.35 A, the battery will supply power for 20 hours, and the total capacity is actually 7 Ah.
However, if you draw 1A, you can expect 7 hours of usage, and you won't get that. Higher currents reduce capacity to some extent. You might also think that you can drag 7A for 1 hour, and that is far from the truth. At this high discharge rate, you may get half an hour, not 1 hour, of use.
The battery likely can supply the 7A safely (this is considered the "1C" discharge rate, as it is 1 times the capacity rating); Check the datasheet to make sure. Just not expected to last very long in that present
Like is it suitable for your motors, is there a peak current that can be pulled by the motors? How long do you want them to run before recharging the batteries? A battery of the size you are discussing will run toy-car shaped motors for a very long time. This can power the motors of a small robot for a few minutes. It would not be suitable for a lawnmower or golf cart at all.
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Thank you for reading.