The Sony FX3 and FX30 both run on the NP-FZ100, shared across the A7 and A9 lines. But a cinema body drains on a different rhythm than a stills camera. A 2280mAh pack rated around 16.4Wh often runs out in a bit over an hour of continuous recording, and that window shrinks further once the cooling fan, monitoring and accessories come into play.
So video power is usually a combination: several NP-FZ100 cells for moving shots, a dummy battery and adapter for locked-off takes, and a power bank for location work. A sensible starting point is two cells plus a dual charger, with a dummy battery added for static setups.
Why Video Bodies Drain Faster Than Stills Bodies
Stills shooting is pulsed. Current spikes when you press the shutter, then the body idles down between frames. Recording is continuous: sensor, processor, encoder and screen all stay loaded, and on the FX3 an active cooling fan runs alongside them. The same capacity delivers far less wall-clock time recording than the CIPA frame count suggests.
Accessories widen the gap. External monitors, wireless transmission, microphones and gimbal power either draw from the body or add system load. Budget around roughly one cell per hour of recording rather than assuming a single battery can carry a day.
Picking Between the Three Approaches
| Approach | Best for | Upside | Watch out for |
|---|---|---|---|
| Multiple NP-FZ100 cells | Handheld, gimbal, run-and-gun | Full mobility; swaps take seconds, no cabling | You need enough cells; each swap interrupts the take |
| Dummy battery + adapter | Locked-off interviews, streaming, timelapse | Unlimited runtime; no battery heat inside the body | Voltage and connector must match; secure the cable |
| Power bank / USB power | Field work, car rigs, no mains access | Mobility plus endurance; tops up while rolling | Confirm the body’s input spec; keep cables short and solid |
In practice these overlap. Handheld on the street runs on cells. Sit down for an interview and you plug in. Transit between locations is when a power bank earns its keep. Filling all three slots costs less than you might expect: our NP-FZ100 two-battery kit runs about $36.74, and adding a single cell at about $17.89 covers most mobile work.
Estimating Runtime on the FX3 and FX30
No single number survives contact with reality — resolution, bitrate, frame rate, stabilization, screen brightness and ambient temperature all move it. Plan around a range of roughly one to two hours of continuous recording per cell, then leave about 30 percent headroom. High-bitrate 4K with active cooling sits at the low end; 1080p or stop-start shooting shifts toward the top.
The official CIPA figures usually sit between 500 and 700 frames, and real use commonly lands around 60 to 80 percent of that, with video lower again. Capacity scales roughly linearly with record time: the 2400mAh TNP-FZ100 adds about 5 percent over the 2280mAh version, meaning a few extra minutes. The reasoning is laid out in 2280mAh vs 2400mAh explained.
Choosing a Dummy Battery: Voltage, Connector, Wattage
- Match the voltage. The NP-FZ100 is nominally 7.2V. Do not substitute another spec.
- Confirm the connector. Barrel DC and USB-C are the common options. Check what your body or cage accepts, and make sure the cable reaches.
- Leave power headroom. The adapter or power bank should exceed the camera’s actual draw while recording, otherwise you can lose charge even while plugged in.
- Secure the cable. A dummy battery lead exits the battery door and gets snagged easily. Zip-tie or clamp it to the cage so a tug cannot damage the contacts.
- Keep one real cell anyway. Even on a dummy battery setup, carry a charged NP-FZ100. Power drops and quick moves should not shut down the position.
For high-frame-rate and burst-heavy power demands on Sony’s speed bodies, see NP-FZ100 and the Sony A9 III.
Power Banks: What Matters
A lot of FX3 and FX30 owners treat a power bank as standard kit. When the body accepts external power, you can shoot and top up at the same time, and even recharge cells with the camera off. Three things decide the purchase: enough output wattage, decent cable quality, and a capacity-to-size balance you are willing to carry. A 10,000 to 20,000mAh bank stays compact and gives several partial refills.
One caution: running on external power keeps the body working, so heat builds. In summer outdoor shoots, watch ventilation and shade, and drop the recording spec or take breaks when needed. Battery temperature needs managing too. Below about 32°F capacity drops noticeably, and near 14°F you may get roughly half the normal runtime. Heat ages cells faster. Rotation and environment control help with both.
A Shoot-Day Power Checklist
- Primary cells: three NP-FZ100 minimum, with two on set and one on the charger.
- Charger: one dual unit for overnight refill. A standalone charger costs roughly $5 more than a bare cell.
- Locked-off positions: one dummy battery kit plus adapter or a large power bank.
- Storage: terminal covers or separate slots per cell to prevent shorts; keep them away from keys and coins.
- Labeling: number each cell and track cycles. Retire anything that runs visibly short rather than discovering it mid-shoot.
FAQ
Do the FX3 and FX30 share batteries?
Yes. Both take the NP-FZ100, so genuine and compatible cells swap between them.
Can I swap cells mid-recording?
Not advised. Cutting power during a take risks corrupting the file. Stop recording, power down, swap, then roll the next take.
Will a dummy battery damage the camera?
External power is standard practice when voltage, connector and wattage match. Pay attention to strain relief and keeping connectors out of moisture, and avoid cheap supplies with unstable output. Skip bare connections in wet or dusty conditions.
How much 4K does one cell record?
Bitrate, frame rate, temperature and stabilization all matter, so figure on roughly one to two hours. Run one test at your actual settings and log the time for scheduling.
Bottom Line
Video power comes down to a simple split: hand uncertainty to external power, keep mobility on cells. Our NP-FZ100 compatible cells run about $17.89 each, about $22.93 as a one-battery kit and about $36.74 for two with a charger. Pair that with a dummy battery for locked-off work and a power bank outdoors and most shoot days are covered. If you want more per-cell headroom, the 2400mAh TNP-FZ100 costs about $19.66 per cell and about $39.92 for two with a charger. Studios, rental houses and production teams ordering 100 units or more should use our wholesale inquiry for volume pricing.