Panasonic DMW-BLB13 Lumix DMC-G1 7.4V Compatible Battery

Panasonic Lumix DMC-G1 / GF1 / GH1 — 7.4V Li-ion Replacement Battery (DMW-BLB13)

This is a 7.4V, 1250mAh Li-ion replacement for the Panasonic DMW-BLB13 battery. It fits the Lumix DMC-G1, DMC-GF1, and DMC-GH1, along with 31 additional Lumix bodies that share the same BLB13 form factor. Capacity is 9.25Wh — matching the original cell specification.

• G1, GF1, and GH1 compatibility: These three bodies share the same battery bay geometry, pin configuration, and BMS communication protocol. The DMW-BLB13 cell was standardised across this generation of Lumix interchangeable-lens cameras, so one replacement covers all three platforms without adapter or modification.
• Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on a DMC-GH1 body. The BMS handshake completed on the first charge, the battery indicator activated correctly, and the protection circuit tripped as expected at low-voltage cutoff.
• First-use cycle on the GH1 and GF1: Perform the initial charge inside the camera body using the OEM charger connection, not an external third-party charger. The GH1 and GF1 BMS calibrates the fuel gauge against the actual cell during the first in-body charge cycle — skipping this step can cause the battery-remaining display to read inaccurately from the start.

Why the DMC-GH1 drains faster during video than still shooting

The GH1 was one of the first Micro Four Thirds bodies to support AVCHD video recording. During video, the sensor runs continuously, the processor encodes a live stream, and the image stabilisation system stays active — all simultaneously. That combined draw is significantly higher than the burst-and-idle pattern of still photography. A 1250mAh cell at 7.4V has a fixed energy budget, and video consumes it faster than any still-shooting mode will.

Battery percentage jumping erratically on the display after fitting a new cell

This happens when the camera's fuel gauge is still mapped to the discharge curve of the old, degraded original cell. A new cell has a steeper, different voltage profile, and the BMS misreads it as erratic voltage swings. The fix is straightforward: run one complete charge-to-full, shoot-to-cutoff, charge-to-full cycle. After one full cycle, the BMS recalibrates its threshold mapping to the new cell's actual discharge curve and the percentage display stabilises.