A02B-0309-K102 A98L-0031-0026 FANUC Battery A98L00310026 A98L-OO31-OO26

A02B-0309-K102 | FANUC CNC Lithium Battery — 3V / 1750mAh / Hard Case / 3-Pin Connector / FS0i-MD/MF / A98L-0031-0026

A02B-0309-K102 — SRAM Backup Battery for FANUC FS0i CNC

The A02B-0309-K102 is FANUC's lithium battery cartridge for CNC system SRAM memory backup in the FS0i-MD, FS0i-MF, and related FANUC 0i series CNC controllers. It retains the complete CNC memory content — programme, parameters, and system data — through power-off periods, maintenance shutdowns, and power failures.

The hard plastic case distinguishes A02B-0309-K102 from the wire-lead battery packs used in other FANUC systems — the cartridge-style housing integrates the lithium cell, protection circuitry, and 3-pin connector into a rigid, self-contained unit that slides into the CNC controller's dedicated battery compartment.

Key Specifications

Hard Case Cartridge — Installation Format

The A02B-0309-K102's hard plastic case provides:

Structural protection: The rigid housing protects the internal lithium cell and circuits from mechanical damage during installation and removal — important in a battery that requires periodic removal from an accessible slot in the CNC controller.

Defined form factor: The cartridge dimensions (45.37 × 20.72 × 38.16mm) match the specific battery compartment in compatible FANUC controllers exactly — the battery slides in and latches without requiring connector manipulation.

3-pin connector integration: The 3-pin connector is moulded into the cartridge end — providing a polarised, positive-latch electrical connection that prevents incorrect installation.

Application Scenarios

FS0i-MD battery alarm: A FANUC FS0i-MD controlled machining centre displays a battery alarm on the operator panel. The A02B-0309-K102 hard case cartridge is removed from its compartment and replaced with a new unit — the 3-pin connector ensures correct polarity. All CNC data retained.

Planned maintenance replacement: The CNC maintenance schedule calls for battery replacement on a 3-year cycle. A02B-0309-K102 is replaced during the next planned production stoppage — proactive replacement before the alarm eliminates any risk of unplanned data loss.

FAQ

Q1: What FANUC alarm indicates A02B-0309-K102 needs replacement?

The FS0i and related FANUC CNCs generate alarm 9F (or equivalent battery alarm) when the A02B-0309-K102 voltage falls below the detection threshold. The alarm typically appears at power-on. Replace promptly — the alarm appears before battery depletion causes SRAM data loss.

Q2: Can A02B-0309-K102 be replaced with CNC power on?

Yes. With CNC power on, the main power supply maintains SRAM — the battery cartridge can be removed and replaced without data loss. Slide the new A02B-0309-K102 into the compartment and connect the 3-pin connector before the old one is removed where the compartment allows. Replacement with CNC power off risks data loss if the gap exceeds the SRAM hold-up time.

Q3: What is the difference between A02B-0309-K102 and A02B-0200-K102?

Both are FANUC 3V lithium battery assemblies for CNC memory backup, but they serve different controller families and use different form factors and connectors. A02B-0309-K102 (A98L-0031-0026) uses a 3-pin connector hard-case cartridge for FS0i-series controllers; A02B-0200-K102 (A98L-0031-0012) uses a different cell and connector for Series 15/16/18 and related controllers. Always confirm the part number from the CNC's battery compartment label before ordering.

Q4: How long does A02B-0309-K102 last in a FANUC FS0i CNC?

Typically 3–5 years in normal CNC service. The battery discharges only while the CNC is powered off. A machine running 24/7 will extend battery life; machines powered off for nights and weekends discharge faster. Replace at the battery alarm, or on a scheduled 3-year maintenance cycle — whichever comes first.