> with fake justifications for the added weight from the explosives.

There was negligible weight increase, as the battery was significantly shrunk to allow hiding the explosive inside [1].

> At some point, Hezbollah noticed the battery was draining faster than expected, the Lebanese source said. However, the issue did not appear to raise major security concerns - the group was still handing its members the pagers hours before the attack.

[1] https://www.reuters.com/graphics/ISRAEL-PALESTINIANS/HEZBOLL...