The quick version: Sony’s mirrorless and compact cameras rely on three mutually incompatible battery standards — NP-FW50, NP-FZ100, and NP-BX1. FW50 covers the early and entry-level bodies, FZ100 covers everything from the third generation upward, and BX1 covers the RX100 family and similar compacts. None of the three swaps with another: size, contacts, voltage, and capacity all differ, and there is no adapter. The only reliable way to identify yours is the printing on your current pack or the spec page of your manual — never the series name, sensor size, or release year. Below is one table covering the specs, then a family-by-family walkthrough, followed by a method that keeps you from getting it wrong. Model-specific confusion is handled in does NP-FZ100 work on the A6400.
Spec comparison across the three families
| Item | NP-FW50 | NP-FZ100 | NP-BX1 |
|---|---|---|---|
| Positioning | Early / entry-level mirrorless | Current-generation mid and high tier | Compact / RX-series cameras |
| Rated capacity | Around 1000mAh class | 2280mAh (third-party versions commonly up to 2400mAh) | Around 1200mAh class |
| Nominal voltage | Around 7.2V | 7.2V | Around 3.6V |
| Energy | Roughly half an FZ100 | About 16.4Wh | Below FW50 |
| Size | Medium | Largest | Smallest |
| Representative bodies | A6000, A6300, A6400, A6500, A5100, A5000, A7, A7 II, A7R II, A7S II | A7 III, A7R III/IV/V, A7 IV, A7S III, A9 series, A1, A6600, A6700, A7C series, FX3, FX30, ZV-E1 | RX100 series plus some compacts and action cams |
| Interchangeability | None across families; packs swap only within the same family | ||
One naming note: TNP-FZ100 is not a fourth standard. It’s a third-party manufacturer’s label for the NP-FZ100 form factor — same electrical spec, same shell, fully interchangeable. The naming logic is explained in is TNP-FZ100 the same as NP-FZ100.
NP-FW50: the early and entry-level family
- APS-C: A6000, A6300, A6400, A6500, A5100, A5000, and several NEX models
- Early full-frame: A7, A7 II, A7R II, A7S II
Capacity here is modest, so runtime per pack is limited and the workable strategy is simply carrying more of them. Look for the NP-FW50 marking and ignore listings that say “fits all Sony mirrorless” — that phrasing is inaccurate.
NP-FZ100: the current main family
- Full-frame / flagship: A7 III, A7R III, A7R IV, A7R V, A7 IV, A7S III, A9, A9 II, A9 III, A1
- APS-C / compact: A6600, A6700, A7C, A7C II, A7CR
- Video bodies: FX3, FX30, ZV-E1
From the third generation onward Sony consolidated its main bodies on FZ100, roughly doubling the energy of an FW50. That move explains most of the improvement in stamina talk since the A7 III. Our NP-FZ100 compatible battery covers every body above at 2280mAh / 7.2V / about 16.4Wh.
NP-BX1: the compact family
The RX100 line plus some Sony compacts and action cameras use NP-BX1. At around 3.6V and the smallest footprint of the three, it has zero interchange with either mirrorless family. RX100 owners should just look for BX1 and not experiment on the assumption that “both are Sony cameras.”
How the split works, and how to choose
Three patterns behind the split
- Power draw decides it, not sensor size. The A7 II is full-frame and takes FW50; the A6600 is APS-C and takes FZ100. Design and consumption are the real criteria.
- Switches happen at generation boundaries. A7 II → A7 III and A6500 → A6600 both changed batteries, which is exactly where buying errors cluster.
- A small body doesn’t imply a small battery. The A7C family is tiny yet uses FZ100 — and benefits from it.
Those three rules account for nearly every “these should share a battery but don’t” puzzle.
A three-step check that never fails
- Read the label. Pull the battery and read FW50, FZ100, or BX1 off the shell. That’s the definitive answer.
- Check the spec page. Your manual’s power or specifications section names the battery — essential verification on secondhand bodies.
- Verify against the listing. Your exact camera model should appear in the compatibility list. Phrases like “same series works too” don’t qualify.
Owning multiple bodies? Bag them separately and label each family. Grabbing a look-alike pack from the wrong pouch is the classic on-location mistake.
Care habits that apply to all three
- Official CIPA figures typically land in the 500–700 frame range; real-world use generally returns 60%–80% of that, less with video and bursts.
- Lithium cells retain roughly 80% after 300–500 cycles, so a noticeable drop after a year is normal wear — think replacement around two years,.
- For storage, hold 40%–60% charge in a cool, dry spot at 15–25°C and top up every three months.
- Below freezing, capacity falls sharply; at -10°C expect around half. Body heat and rotation help.
- Retire anything swollen and route it to a recycling stream. No puncturing, no burning.
- Flying: any spare under 100Wh goes in carry-on, never checked, with terminals protected.
FAQ
Is one family “higher grade” than the others?
There’s no hierarchy, only different cameras. FZ100 stores the most energy, but it only fits FZ100 bodies. Same logic for FW50 and BX1.
Do third-party packs use different part numbers?
Often, with prefixes added — TNP-FZ100 being one. As long as the spec matches and the compatibility list includes your body, they interchange normally.
What should I do with old packs after switching bodies?
Keep them if your new camera shares the standard; otherwise pass them on with the old camera or keep them for that body. Anything unusable goes to recycling.
How can I tell whether a pack is original?
Look at build quality, print sharpness, and packaging claims, then test whether it shoots cleanly and reports charge sensibly. Some Sony bodies warn that remaining charge may display inaccurately with compatible packs, which is fine and doesn’t affect shooting.
Bottom line and buying notes
Fix this order in your head: read your existing pack → confirm FW50, FZ100, or BX1 → choose a quantity based on how you shoot. In the FZ100 camp, YO’s NP-FZ100 compatible battery (2280mAh / 7.2V / about 16.4Wh) is around $17.89, about $22.93 for one battery with a charger, and about $36.74 for two with a charger. The TNP-FZ100 (2400mAh / about 17.3Wh) adds margin at around $19.66, or about $39.92 as a two-battery kit. Sony’s own replacement costs $70 and up. Full cross-reference table in the Sony mirrorless battery chart. Studios, rental houses, and resellers needing 100 units or more should request pricing through the wholesale inquiry page.