Those appear to be high brightness LEDs but without a data sheet no one would know.
Leds require a certain voltage to work along with needing to have current limiting to the design spec.
You can run LEDs at a much lower current than the maximum advertised without a noticable visual difference.
The above current limiting can be achieved several ways and it depends on the LEDs used as to which is best/cheapest/simplist.
Flashing the LEDs on and off will result in much less power usage over a given time and the amount depends on the frequency of on to off time.
This also can be achieved in several ways.
If the project starts to get more involved (i.e. sensors for whatever) it would become more appropriate to use a small microcontroller such as say an Arduino Nano or Promini but at this stage I think your discrete devices will suffice. The micros can be put to sleep when required and so current draw is then about 2 knobs of stuff all.(microAmps)
For your future reference, if you are working with batteries/cells then batteryuniversity web site fully explains the expected capacity etc. etc.
It's not all what you read on the label or, for that matter, what Amazon or other similar sites tend to shove in ones face.
https://batteryuniversity.com/