1.3.1 Batteries must be of a construction that is spill proof in all orientations. Suggested battery types are Nickel Cadmium, Nickle Metal hydride and Lithium Polymer. Immobilized electrolyte (gel-cell or absorbed glass mat) lead-acid batteries may be used as well.

1.3.2 Batteries using exotic chemistry or construction that can result in the release of toxic gas or liquid are not allowed. If in doubt about the battery type you wish to use contact the event organizer.

1.3.3 Battery voltage is limited to 48V. This is defined as the rated voltage of the battery array. Tournament organizers may specify a different voltage limit.

1.4 Radio Control. Robots are normally controlled by radio systems operating in approved frequency bands for ground vehicles in the country where the tournament is held.

1.4.1 Common frequency bands for ground vehicles are 75MHz (hobby R/C) and the 900MHz and 2.4GHz ISM bands. 72MHz band R/C radios are restricted to air vehicles and may not be used for Bot Hockey matches. Other frequency bands such as 50MHz, 433 MHz and 27MHz / 49MHz bands may also be used. Tournament organizers may disallow use of radios operating in some of these bands. Countries outside the US will have different frequency bands allowed for use. Teams are responsible to ensure their robots meet the radio requirements of the tournament. Tournament organizers will explicitly announce any restrictions or changes to the common frequency bands (75MHz, 900MHz, 2.4GHz, 49MHz and 27MHz).

1.4.2 Any type of frequency modulation may be used to control Bot Hockey robots. Specifically low-cost AM and toy style radios are allowed for all classes. Tournament organizers may restrict modulation types for safety or other reasons.

1.4.3 Digital data modem radios, wireless networking, or other types of data radios are allowed consistent with frequency band requirements in the country where the tournament is held. Tournament organizers may restrict some types of data communications such as wireless network adapters that might interfere with tournament data systems.

1.5 Other Control Systems. Other types of control systems such as infrared, ultrasonic, or laser may be used subject to approval by the tournament organizer. In general, non-radio control systems must be eye-safe for players and spectators and not disrupt the conduct of the tournament e.g. audible sound-based systems. Teams wishing to use non-radio control systems must receive approval from the tournament organizer before using the system.

1.6 Weapons. Bot Hockey robots should not have weapons or devices intended for damaging the competitor robots, the playing field, or the puck. At the tournament  organizer’s discretion any robot may be disqualified if it is deemed to violate the spirit of this rule even if the robot otherwise meets the letter of the rules below.