Sony

Short answer: one 2600mAh NP-FZ100 gives you roughly 400–500 frames of street shooting, 350–420 at a wedding, and 85–100 minutes of continuous 4K 25p. What actually decides your runtime is not the cell — it is screen brightness, stabilisation, wireless, and how long the camera sits switched on waiting.

Runtime by shoot type

These are working ranges from ordinary use, not lab figures. Temperature, lens stabilisation and shooting intensity will move them by ten to fifteen percent either way. Treat them as planning numbers.

Shoot	One cell lasts	Main drain
Street (on for 10–20s, off between shots)	400–500 frames / 3–4 hours	EVF, boot cycle
Travel (frequent review, on and off)	350–450 frames / 2.5–3.5 hours	Review, brightness, Wi-Fi
Wedding / event (always on)	350–420 frames / 2–3 hours	IBIS, bursts, AF-C
4K 25p continuous	85–100 minutes	Encoder, heat, screen
1080p continuous	120–140 minutes	Encoder, screen

One thing gets overlooked: idling costs power. Mount a stabilised 70-200 and the OIS, AF and IBIS keep working between frames. Four hours on the floor of a venue with only 300 frames shot is a completely normal consumption pattern.

Five settings that buy back power

• Fix screen brightness at mid. Auto brightness pins to maximum outdoors; this alone saves ten to fifteen percent.
• Turn off high frame rate display. Standard refresh in the finder saves power with almost no cost to the focusing experience.
• Disable Wi-Fi and Bluetooth auto-connect. Forgetting to turn Wi-Fi off is the most common cause of a dead spare, especially with FTP enabled.
• Set power save to one minute. The a7 IV wakes in about 0.3 seconds, far cheaper than leaving the screen lit.
• Switch IBIS off when it is not earning its keep. On a tripod, or above 1/500s, it is pure waste.

Together these typically return 60 to 100 extra frames in a wedding — about a third of a battery, for free.

Charging beats buying

Most “battery problems” are really scheduling problems. The a7 IV charges over USB-C PD and runs on USB power while shooting, so with a 30W-or-better power bank you can top up in any gap.

Method	Speed	When
In-body USB-C, PD 30W	About 2.5 hours to full	Lunch, car, hotel
In-body USB-C, plain 5V	Six hours or more	Not worth it
Dedicated dual charger	Two cells in about 2 hours	Overnight, batch
Dummy battery + power bank	Unlimited while plugged in	Static setups, livestreams, long interviews

The economical setup is two cells, one dual charger and a 65W power bank. Rotate during the day, top up in gaps, charge both overnight. It costs far less than four batteries and weighs less too.

When a dummy battery makes more sense

If the camera does not move — interviews, livestreams, conferences, timelapse — the DR-FZ100 dummy battery beats stacking cells. Power comes from an external bank, so a 20000mAh pack runs all day and the body never thermally derates from a hot cell in the grip.

The trade-off is cabling: you need to dress the cable, match the voltage spec, and it is awkward for handheld work. Sit-down shoots only.

FAQ

Can one a7 IV battery last a full day?

Light street shooting, yes. A full travel day or an event, no. Plan on two cells minimum and three to four for anything where you cannot miss a moment — a swap takes ten seconds and does not interrupt the shoot.

Does charging while shooting slow the a7 IV down?

No performance penalty, but you need PD 30W or higher to run the body and charge at once. On a plain 5V charger the percentage still falls, just more slowly.

How should I store batteries I am not using?

Keep them at 50–60 percent and top up every three to six months. Storing at full charge or fully flat accelerates ageing and shows up as obvious capacity loss after two years.

The setup we would buy

On a budget, get to three cells first: the 2600mAh NP-FZ100 is inexpensive enough that three plus a dual charger covers a full wedding or a three-day trip.

If your a7 IV is mostly a video body, start with two cells and a DR-FZ100 — external power for the locked-off takes, cells for handheld, which matches how a shooting day actually runs. Bodies like the a7C II take the same cell, so multi-body kits can share one battery pool.

Short answer: the Sony a7 IV runs on an NP-FZ100 — 7.4V, 2600mAh / 19.24Wh in the high-capacity YO version, against 2280mAh / 16.4Wh for the OEM pack. Sony rates it at roughly 580 shots on the LCD, 520 through the viewfinder. Carry one spare for street work, three or four for a wedding, and budget about 90 minutes of 4K recording per cell.

What the NP-FZ100 actually is

The a7 IV arrived in late 2021: 33MP full frame, dual slots for CFexpress Type A and SD, a side-flip screen, 4K 60p. Its power system is inherited wholesale from the a7 III, which is good news if you already own that body — your cells carry over without an adapter.

Spec	On the a7 IV
Cell code	NP-FZ100 (BC-QZ1 is Sony’s matching charger)
Voltage	7.4V nominal (Sony prints 7.2V; same discharge window)
Capacity / energy	2600mAh / 19.24Wh typical; 2400mAh / 17.76Wh rated
In-body charging	Yes, USB-C PD — and USB power while shooting
Shared with	a1, a9 series, a7 III / a7R III / a7R IV / a7R V / a7S III / a7C / a7C II, a6700, a6600, ZV-E1, FX3, FX30

An OEM NP-FZ100 is 2280mAh / 16.4Wh. Third-party high-capacity packs land at 2400–2600mAh, about ten percent more on paper. Do not expect that percentage to convert one-to-one into frames: cell discharge curves and the protection board’s cutoff voltage decide the real number. Eight to twelve percent more shooting time is a realistic expectation, not twenty.

Why your 580-shot number looks like 300

CIPA measures under fixed conditions: 23°C, default screen brightness, one frame every 30 seconds, flash on every other frame, power cycled every ten. Real shoots drain in four different places.

• Viewfinder versus screen. A constantly live EVF draws more than the LCD — that is exactly why the rating drops from 580 to 520.
• Brightness and refresh. Max brightness outdoors plus high frame rate display adds roughly twenty percent.
• IBIS and bursts. Stabilisation stays energised, and continuous shooting keeps sensor readout and processor pinned. This is the one event shooters underestimate.
• Wireless. Wi-Fi, Bluetooth, FTP upload and phone tethering are all silent drains. Leaving Wi-Fi on after a shoot is the single fastest way to lose a bar.

For weddings and events — camera on, waiting for the moment — expect 60 to 75 percent of the CIPA figure, so 350 to 430 frames. Video is starker: about 90 minutes of continuous 4K 25p, less with IBIS on, an external monitor attached, or a hot afternoon.

How many cells to carry

Shoot	One cell enough?	Carry	Note
Half-day street	Yes	1 + power bank	Top up via USB-C on the way back; 30W PD or better
Full-day travel	No	2	Dual charger overnight, both cells full at breakfast
Wedding / event	No	3–4	Two in a pocket, swap in ten seconds
Talking head, locked off	Depends	2 + dummy battery	Long takes: DR-FZ100 into a power bank
Long 4K / livestream	No	2 + dummy	No thermal derating from a hot cell inside the body

Will a third-party NP-FZ100 work?

Yes, and in most situations you will not notice a difference. There is one criterion that matters: does it have a decoding chip? A decoded pack talks to the body, the percentage counts down normally, and low-battery warnings behave. An undecoded “bare cell” shows only four bars on the a7 IV and can cut out at two — exactly the behaviour you do not want mid-ceremony.

Two related questions come up constantly. Firmware updates may produce a one-time “cannot guarantee battery performance” notice on power-up; confirm it and shooting continues. And in-body USB-C charging generally works with third-party cells, but the speed depends on the charger supporting PD — a plain 5V brick charges painfully slowly.

FAQ

Is the a7 IV battery the same as the a7 III?

Yes. Both use the NP-FZ100, so cells from an a7 III, a7R III or a7R IV fit the a7 IV and vice versa. Older cells will hold noticeably less than their rated capacity after years of cycling, so keep the newest pack on the main body.

How long can the a7 IV record 4K on one battery?

About 90 minutes of continuous 4K 25p, less with IBIS active, an external monitor, or high ambient temperature. For interviews and livestreams a dummy battery into a power bank removes the limit entirely.

Does a third-party battery void the camera warranty?

No. Batteries are consumables and using a third-party pack does not affect the body warranty. Damage caused by a swollen or leaking cell is not covered, which is why unbranded bargain cells are a false economy.

What to buy

If you simply need a spare, a single 2600mAh NP-FZ100 is the cheapest way to fix it — about ten percent more capacity than OEM at a fraction of the price.

Shooting events regularly? A two-cell kit plus a dual charger pays for itself: both cells full overnight, no fighting over the one socket in a hotel room. If you would rather leave the charger at home, the full NP-FZ100 range puts single cells, two-cell kits and chargers on one page.

Still own an a7 III or a7R III? Same cell, so the a7 III battery page applies to you too — accessories swap in both directions.

Short answer: a third-party NP-FZ100 works in the a7 IV as long as three things hold — it has a decoding chip, the percentage counts down properly, and in-body USB-C charging works. A decoded pack is indistinguishable in use. An undecoded cheap cell will jump from 45 percent to shutdown, and that is not a battery you want in front of a client.

Three kinds of “compatible”, very different results

Type	Charge display	Behaviour in the a7 IV	Verdict
Decoded standard pack	Percentage, step by step	Essentially OEM; occasional boot notice	Recommended
Undecoded bare cell	Four bars only	Can cut out at two bars	Avoid for paid work
USB-C direct-charge pack	Percentage, normal	Charges off-camera; slightly lower capacity	Good for travel

Most listings say “supports battery level display” rather than “decoded”. That phrase is the tell: a seller willing to claim in-body percentage display is almost always shipping a decoded pack. Listings that only say “fully compatible” and stay quiet about the level indicator deserve suspicion.

What the firmware notice really means

Certain firmware versions show a one-time message on power-up with a non-OEM cell, roughly “cannot guarantee the performance of this battery”. It is not an error and it does not refuse to operate — it is a disclaimer. Confirm it and stills, video and playback all behave normally.

A different message matters: “battery not recognised” or an immediate 0 percent. That means the handshake failed at the hardware level. Stop using that pack in the a7 IV — not because it will damage the body, but because you cannot predict runtime during a shoot.

Testing whether the percentage is honest

Run one full discharge: fit the cell, record 1080p continuously until the camera shuts itself down, and watch the curve. A healthy pack falls smoothly, with the last ten percent going a little faster. A pack that jumps from 45 to 15, or dies at 20, has a protection board guessing rather than measuring — common with rebuilt or refurbished cells.

After that discharge, charge it fully once and the body recalculates. Do this with every new battery, then every three to six months. There is no need for frequent deep cycling.

Three conditions for in-body charging

• A cable with data and power lines. Charge-only cables lack the PD negotiation and the body simply refuses.
• A PD charger at 30W or more. Below that the a7 IV falls back to slow charging.
• Protection circuitry in the pack. Decoded packs all support in-body charging; the cheapest unprotected cells may stall halfway or never reach full.

Measured here, the 2600mAh pack fills in about 2.5 hours on a 30W PD charger — effectively identical to OEM. A 65W charger will not be faster; the body caps the input.

Four details worth checking before you buy

1. Read rated, not just typical. 2400mAh rated over 2600mAh typical is the industry norm. A “3200mAh” pack at a third of the price is usually inflating the typical figure.
2. Shell tolerance. It should slide in and latch cleanly. A pack that wobbles will wear the body’s contacts over years of use.
3. Cycle life. Reputable packs state 80 percent capacity after 500 cycles. No figure, no purchase.
4. Over-charge, over-discharge and over-temperature protection. These are the safety floor, especially in a hot car in summer.

FAQ

Can a third-party battery damage the a7 IV?

A decoded pack with protection circuitry cannot. The risk sits with unprotected bargain cells: over-charging, swelling and leakage are what damage a battery compartment. Buy something that states capacity and cycle life and most of that risk disappears.

Why does my third-party cell only show four bars in the a7 IV?

That pack has no decoding chip, so the body falls back to rough voltage bands. It can shut down without warning near the end, which makes it unsuitable for weddings or any shoot that cannot be interrupted.

One cell or a two-cell kit?

One is enough as a spare. If you shoot events regularly, the two-cell kit with a dual charger pays off: rotate during the day, both full overnight. The packs are identical and both seat correctly in the a7 IV.

The simple choice

If you would rather not research specs, the YO 2600mAh NP-FZ100 is a decoded pack: in-body charging works, percentage reads normally, capacity is about ten percent above OEM at roughly a third of the price.

If you travel and resent carrying a charger, take the two-cell kit — two packs plus a dual charger, one socket in the hotel room.

Running an a7 III alongside the a7 IV? Same cell, so check the a7 III battery page — one pool of batteries covers both bodies.