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Electrical & Wiring·Lesson 9 of 34

The 12V SLA Battery and Anderson Connectors

Everything about the FRC battery: specs, legal rules, the Anderson SB connector, and battery care.

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The FRC battery

FRC robots run on a single 12V, non-spillable Sealed Lead Acid (SLA) battery. When fully charged it can briefly supply over 180A - which is why insulation and a main breaker are mandatory. Rule R601 requires exactly one non-spillable SLA battery with nominal 12V, a 20-hour-rate capacity of 17-18.2 Ah, rectangular shape, nut-and-bolt terminals, and (new for 2026) unobstructed vents.

The manual lists specific legal examples, including the MK Battery ES17-12, Enersys NP18-12 / NP18-12B / NP18-12BFR, Power Sonic PS-12180NB, and Yuasa NP18-12B - always confirm against the current Game Manual's list.

The Anderson SB connector

The battery connects to the robot through an Anderson Power Products (APP) SB-type connector - the standard is the SB50. Kit-of-Parts batteries ship with a red or pink SB50 so teams and field equipment interoperate (the pink KOP connectors mate with red SB50s). Rule R603 requires battery chargers to use the matching Anderson SB connector so charging is safe and consistent.

Battery lead wiring rules (R609, R607):

  • 6 AWG copper wire or larger for the leads.
  • All terminals and connections - on the battery, the main breaker, and their lugs/stripped ends - fully insulated at all times (R607).
  • Proper color coding for the leads (red/yellow/white/brown/black-with-stripe for positive; black or blue for negative) per R624.

Charging and care

  • R604 caps average charge current at 6A; chargers rated over 6A are banned from FRC pits.
  • A good battery has internal resistance under ~0.015 ohms (manufacturer spec ~0.011). If a battery climbs above ~0.020 ohms, retire it from competition matches.
  • SLA cells are rated for ~1200 cycles, but FRC's high currents cut usable competition life to roughly 400 cycles.
  • Use a battery tester (e.g. a Battery Beak) to measure resting voltage and internal resistance before matches. A battery reading ~12.5V at idle should be charged before use.

Securing the battery

Rule R606 requires the battery to be secured so it cannot dislodge during vigorous robot interaction (including if the robot tips), and R605 forbids using extra batteries as ballast. Use a strap or bracket plus hook-and-loop, and route the leads so they cannot snag.

Sources

Key takeaways

  • FRC uses one 12V non-spillable SLA battery (R601), 17-18.2 Ah, nut-and-bolt terminals, vents unobstructed (2026); it can briefly supply 180A+.
  • The battery connects via an Anderson SB50 (red/pink KOP) connector with 6 AWG leads, fully insulated (R607/R609).
  • Charge at 6A average or less (R604); retire batteries whose internal resistance exceeds ~0.020 ohms.
  • The battery must be securely mounted (R606) and cannot be used as ballast (R605).

Go deeper

Lesson quiz

Required

Answer all 3 questions correctly to complete this lesson.

1.What chemistry and nominal voltage does the standard FRC robot battery use?

2.Which connector does FIRST strongly recommend teams use to attach the battery to the robot for interoperability?

3.What is the minimum copper wire gauge required for the battery leads ending in the Anderson connector?

Answer every question to submit.