On the 16th and 17th, the standout stars of the Buddha’s Birthday lantern festivities were undoubtedly the ‘robot monks’. Taking part in the downtown parade procession, they walked with palms joined, thrilling onlookers. In particular, when they were spotted performing an ‘electric alms’ mid-parade, many were reminded of the Buddhist traditional practice of ‘balwoo gongyang’.

A total of four robot monks‘Gabi’, ‘Seokga’, ‘Mohui’, and ‘Nisa’marched briskly for 40 minutes over about 2.9㎞ from Heunginjimun (Dongdaemun) to Jogyesa, wearing the jangsam and kasa like real monks. Each time they passed, exclamations broke out among citizens and foreign tourists.

After they received precepts at Jogyesa on the 6th and became the world’s first robot monks, academia and industry also paid close attention. In particular, their method of replenishing energy after a long outdoor event drew interest. In fact, on the 16th, they were spotted performing an ‘electric alms’ in front of Tapgol Park in Seoul. The robot monks moved in single file through the crowd and entered a tent to charge their batteries. Among the spectators, sympathetic comments were heard here and there, such as “Oh my, looks like they are going to charge” and “Did the battery run out? They look tired.”

Experts say the process of absorbing and managing electricity during charging resembles the Buddhist ‘balwoo gongyang’. In balwoo gongyang, monks do not leave food, take only the minimum nutrition needed to sustain the body, and even rinse and drink the last drop of scorched-rice tea to cleanse the bowlan economy with no waste. Just as monks guard against greed and fill their bowls only as needed, a humanoid robot likewise must take in precisely the required amount of power to ensure safety.

The Kyunghyang Shinmun obtained Unitree Robotics’ ‘G1 Official Technical Specifications’ and ‘Smart Battery User Manual’ for the bodies of these robot monks. According to these documents, the battery installed inside the G1 humanoid robot is a lithium-ion battery pack with a capacity of 9000mAh and a total energy of 421.2Wh. Its rated voltage is 46.8V, and the maximum charge voltage reaches 54.6V. Considering that a typical smartphone battery capacity is around 40005000mAh, it is a high-capacity power source capable of running dozens of smartphones simultaneously. Based on this power, the robot monks can continue autonomous walking, conversation, and precise movements such as joining hands for about two hours on a single electric alms.

What also intrigued the industry was the customized precepts given to them by the Jogye Order, the ‘Five Robot Precepts’. At Gabi’s precept ceremony, the Jogye Order imparted the teaching “conserve energy and do not overcharge.” This aligns with the essence of BMS (Battery Management System) technology, on which the global battery industry is staking its future to prevent fires and extend lifespan. If a lithium-ion battery enters an overcharged state by force-feeding it too much energy, internal cell pressure rises and dendrites can form, greatly increasing the risk of fire or explosion.

Indeed, the ‘self-discharge control logic’ described in Unitree’s battery manual resembles Buddhist wisdom that prohibits overeating to aid digestion and keep the body light. Gabi’s built-in battery employs a proprietary advanced BMS that monitors voltage and temperature in real time and automatically blocks overcharging. In addition, if stored long-term for more than 10 days without use, the battery can gradually self-discharge its internal energy to about 65%, the most stable level, to prevent cell degradation and swelling.

It also supports quick-release battery pack swaps optimized for outdoor events. While it takes about 1 hour and 30 minutes to charge a fully depleted battery, Gabi’s backpack-style battery can be replaced with a fresh unit in just a few seconds. Thanks to this, even at long-running outdoor events like the Lantern Parade, the flow was uninterrupted and the practice could continue through swapping spare batteries.

A battery industry official said, “At a time when power shortages and safety issues are emerging as key topics due to the growth of artificial intelligence and high-performance mobility, the robot monk’s method of electric alms shows the path the future robot ecosystem and battery industry must take for sustainability.”