New Panasonic BR-AGCF2W 6V Battery BRAGCF2W

BR-AGCF2W | Panasonic 6V Lithium Battery — 2-Cell / 1800mAh / FANUC Beta SVU / Beta iSV / ABS Circuit Backup

Memory and Absolute Position Backup for FANUC Beta Systems

The BR-AGCF2W is Panasonic's twin-cell 6V lithium battery for FANUC Beta servo amplifiers — used specifically to power the ABS (Absolute Positioning System) circuit within Beta SVU and Beta iSV drives. Two Panasonic BR-A cells connected in series produce the 6V output required by the amplifier's internal CMOS and absolute encoder memory.

In an absolute positioning system, the servo encoder tracks axis position continuously — even when the CNC is powered off. The BR-AGCF2W supplies the low-level standby current the encoder's position counter and memory need to maintain this absolute position data. When power is restored, the CNC reads the retained position directly from the encoder — no reference (homing) run is needed.

Key Specifications

Panasonic BR-A Cells — Why These Specific Cells

The BR-AGCF2W is built with Panasonic's BR-A cells — the OEM cells specified by FANUC for Beta amplifier battery packs. BR cells use lithium poly(carbon monofluoride) chemistry (Li-CFₓ):

Flat discharge curve: Output voltage remains nearly constant from full charge to near depletion — the CMOS and encoder memory receive a stable 6V supply throughout almost the entire battery service life, rather than declining gradually.

Very low self-discharge: Less than 1% per year at 25°C — the battery retains its capacity through 10 years of storage with minimal loss. A freshly installed BR-AGCF2W delivers its rated capacity even years after manufacture.

Wide temperature range: −40°C to +85°C — reliable in all industrial control cabinet environments from cold storage facilities to hot machine rooms.

Application Scenarios

ABS circuit battery alarm on Beta drive: A Beta servo axis on a FANUC-controlled machine displays an ABS battery alarm. The BR-AGCF2W is replaced during planned maintenance — absolute position data retained intact, homing avoided on restart.

CNC machine absolute encoder reset prevention: A machining centre with absolute encoders on all axes requires a homing run only once at initial setup — the BR-AGCF2W maintains all axis absolute positions through every subsequent power cycle.

FAQ

Q1: What is the ABS battery warning alarm on a FANUC Beta amplifier?

The CNC displays an axis-specific alarm (typically code 9F or SV-300 series depending on the CNC type) when the BR-AGCF2W voltage drops below the detection threshold. Replace at the warning alarm — before complete battery depletion causes absolute position data loss and forces a full homing cycle.

Q2: Can BR-AGCF2W be replaced with power on or must the CNC be shut down?

Replace with CNC power on. While powered, the amplifier supply maintains the ABS encoder memory — the battery can be disconnected and reconnected without position data loss. Replacing with power off risks losing absolute position data if the new battery connection takes more than a few seconds.

Q3: What is the difference between BR-AGCF2W (brown connector) and BR-AGCF2P (other connector)?

Both are 6V, 2-cell Panasonic BR-A battery packs — the difference is the connector type. BR-AGCF2W uses the JAE 2-pin connector (brown or black depending on assembly revision); BR-AGCF2P uses a different connector format. Check the amplifier's battery port connector before ordering to confirm the correct variant.

Q4: How long does BR-AGCF2W last in service on a FANUC Beta amplifier?

Typically 3–5 years in normal CNC service. The battery discharges only when the CNC is powered off — machines running 24/7 last longer than those shut down daily. Replace at the battery alarm regardless of elapsed time; do not wait for the alarm to escalate.