what ndi means here is that it uses 180Ws (Watt seconds) not 180W, he just forgets the s at the end (e.g. Ws)

Because as i wrote the BL-5J cannot deliver much in terms of POWER, even in a 1 second spike you wont even get 20W

Now i don't know why he insists on using Ws instead of just Wh.
This then calculates to 10% being drawn in 30 sec = 1320mAh / 10 = 132mAh
In watts thats 132mAh * 3.8V = 0.5Wh that have been draw

But the fact is here that this is equal to 12C for 30sec which i can assure you that the battery or circuit can't handle

Now i know that it does not use 10% on a reboot/boot, because if you measure the battery in REAL TIME then you will see the voltage go up when it is done with the boot, e.g. it "recovers" some %, the real drain is more like max a few %, but why keep speculating, someone here please charge their battery full up, and then do either
10 Boot
20 Wait 10sec after idle
30 Shutdown
40 GOTO 10
or
10 Reboot #after full charge
20 Wait 10sec after idle
30 GOTO 10
and then report back how many boots or reboots the 1320mAh battery can handle, or any other battery you have.