Answer up front: the NP-FZ100 and the NP-FW50 are entirely different batteries — different dimensions, different contact layouts, different capacities — and they cannot be swapped or substituted for one another. They aren’t successive generations of the same product. Sony split its lineup into two families: FW50 for older and entry-level bodies, FZ100 for mid-range and newer ones. The usual mistake sounds like “it’s a Sony mirrorless, so FZ100 must be right.” In reality, the A6000, A6300, A6400, A6500, A7, A7 II, A7R II, and A7S II all run on NP-FW50 and physically cannot take an NP-FZ100, while the RX100 series uses the NP-BX1. Read the printing on your original battery before ordering; if you want the whole lineup explained, start with every Sony mirrorless battery model explained.
Spec comparison
| Item | NP-FZ100 | NP-FW50 |
|---|---|---|
| Positioning | Large capacity; mid-to-high tier and newer bodies | Smaller capacity; earlier and entry-level bodies |
| Rated capacity | 2280mAh (third-party versions commonly 2280–2400mAh) | Around 1000mAh class |
| Nominal voltage / energy | 7.2V / about 16.4Wh | Around 7.2V, roughly half the energy of an FZ100 |
| Shape and contacts | Bigger and thicker, different pin layout | Clearly smaller, different pin layout |
| Representative bodies | A7 III, A7R III/IV/V, A7 IV, A7S III, A9 series, A1, A6600, A6700, A7C series, FX3, FX30, ZV-E1 | A6000, A6300, A6400, A6500, A5100, A5000, A7, A7 II, A7R II, A7S II, plus some NEX models |
| Interchangeable? | No. Neither converts to the other, and no adapter exists | |
| Air travel | 16.4Wh, well under the 100Wh threshold | Equally far below 100Wh; identical airline rules apply |
The short version to remember: roughly double the capacity, visibly larger, contacts don’t line up. Anyone claiming “it fits, therefore it works” can be safely ignored — the size difference alone prevents one from going into the other’s bay.
Why Sony runs two battery families
The reasoning isn’t complicated: different bodies need different power. The early A7 series and A6000 line drew less power and were physically smaller, so FW50 balanced runtime against size. Starting with the A7 III and A9 generation, processors, stabilization, burst rates, and video specs all jumped, taking power draw with them, and a larger pack became mandatory. In other words, a change in battery type is really a marker of a generational shift.
- A7 II → A7 III: FW50 gives way to FZ100.
- A6500 → A6600: the APS-C side makes the same switch.
- The A7C series stays with FZ100 despite its compact shell, and its runtime benefits accordingly.
That also means old batteries generally don’t follow you into a new body. Most people who upgrade end up re-buying their entire battery kit.
Misconceptions worth clearing up
- “The A6400 can use FZ100.” It cannot. The A6400 takes NP-FW50; only the A6600 and A6700 moved to FZ100. Full detail in does NP-FZ100 work on the A6400.
- “A7 II and A7 III share batteries.” They don’t. FW50 for the former, FZ100 for the latter.
- “FZ100 is just the bigger upgrade of FW50.” It isn’t an upgrade path at all; the two are mechanically incompatible.
- “RX100s take a mirrorless battery.” No. The RX100 line uses NP-BX1, a different size and voltage entirely.
- “I bought a third-party FZ100 and the body won’t accept it.” Most compatible packs shoot perfectly. Some Sony bodies show a message along the lines of “remaining charge may not be displayed accurately,” which is normal and doesn’t stop you working. An outright “cannot be used” message is different — that one calls for checking the contacts and whether the pack is properly seated.
Confirming which battery your camera uses
- Read the label on the pack itself. Most reliable method by far: whatever it says is what you buy.
- Check the spec page of the manual. The power or specifications section names the battery.
- Look at the bay. The FW50 compartment is visibly narrower; the FZ100 bay is wider and deeper.
- Don’t infer from series or year. Cross-generational battery changes are common — the A6400 and A6600 sit one apart and share nothing.
Pick by camera model
| If you shoot | Choose | Suggested kit |
|---|---|---|
| A7 III / A7R III / A7R IV / A7R V / A7 IV | NP-FZ100 | Two or three packs plus a dual charger |
| A7S III / A9 series / A1 / FX3 / FX30 / ZV-E1 | NP-FZ100 (video rigs should add external power) | Three or more |
| A6600 / A6700 / A7C / A7C II / A7CR | NP-FZ100 | Two or more |
| A6000 / A6300 / A6400 / A6500 | NP-FW50 — not FZ100 | Two or three FW50 packs |
| A7 / A7 II / A7R II / A7S II | NP-FW50 — not FZ100 | Two or three FW50 packs |
| RX100 series | NP-BX1 | Two BX1 packs |
FAQ
Can I modify an FZ100 to fit my A6400?
No. Size, contacts, and voltage differ; forcing it risks short circuits and a damaged body. Don’t attempt it.
My FW50 body has weak runtime. Will an FZ100 fix that?
There’s no way to fit one. Improve it by carrying more FW50 packs and trimming review time, screen brightness, and unnecessary features.
Do the two need different care?
Basically identical: top up often, avoid living at 100%, store at 40%–60% and recharge every three months. Because the FZ100 holds more energy, a given cycle count covers more frames.
Are the airline rules the same?
Yes. Both sit well under 100Wh, so spares go in carry-on only with protected terminals.
Do third-party cells risk damaging the body?
A properly specified, undamaged pack is fine. Match rated voltage and capacity to spec and retire anything that swells.
Bottom line and buying notes
Memorize one rule: read the label, not the series. If it says NP-FZ100 you need FZ100; if it says NP-FW50 you need FW50 — and every A6000-series body except the A6600 and A6700 falls in the second group. Confirmed FZ100 shooters can look at YO’s NP-FZ100 compatible battery (2280mAh / 7.2V / about 16.4Wh) at around $17.89, with kits at about $22.93 and $36.74. Prefer extra margin? The TNP-FZ100 (2400mAh / about 17.3Wh) is around $19.66, or about $39.92 with two batteries and a charger. Sony’s original goes for $70 and up. The three-family comparison sits in the Sony mirrorless battery cross-reference. Studios, rental houses, and resellers ordering 100 or more should use the wholesale inquiry page.