Short answer: 2280mAh and 2400mAh differ by 120mAh, about 5 percent. In energy terms that is roughly 16.4Wh against 17.3Wh, under 1Wh apart. In use, expect a few dozen extra frames or a few more minutes of video — noticeable in the margins, not a decisive advantage.
So do not agonize over capacity. Ask instead how many cells you need, what the budget is, and how often you run down to empty. Finish the day with a bar left and the 2280mAh is the better buy. If you regularly drain the last cell, 2400mAh gives you a little more slack.
Putting 120mAh in Perspective
| Spec | NP-FZ100 (2280mAh) | TNP-FZ100 (2400mAh) | Difference |
|---|---|---|---|
| Rated capacity | 2280mAh | 2400mAh | +120mAh (about +5%) |
| Rated voltage | 7.2V | 7.2V | Same |
| Energy (Wh) | Around 16.4Wh | Around 17.3Wh | About +0.9Wh |
| Theoretical runtime | Baseline | About 5 percent more | Tens of frames or a few minutes |
| Our price per cell | About $17.89 | About $19.66 | About +$1.77 |
| Two cells + charger | About $36.74 | About $39.92 | About +$3.18 |
Concrete version: if a 2280mAh cell delivers around 500 frames, the 2400mAh version manages roughly 25 more. That figure moves with body, temperature and settings, but it makes the point — capacity differences are polish, not transformation. If you want twice the runtime, carry twice the cells.
mAh, Wh and Voltage: Reading All Three
- mAh (milliamp-hours) is current multiplied by time, describing stored charge. It only compares cleanly at equal voltage: two 7.2V FZ100 cells can be compared directly, while a 7.2V cell against a 3.6V one cannot.
- V (voltage) is the working voltage, set by how cells are wired internally. The NP-FZ100 is nominally 7.2V, and both camera and charger are designed around it. A mismatch is a real hazard.
- Wh (watt-hours) is energy, equal to voltage times amp-hours. Wh is the figure that travels across comparisons, and it is also what the 100Wh airline threshold uses. At around 16.4Wh, spare cells fly in carry-on (never in checked bags).
Memory aid: compare mAh when voltages match, compare Wh when they do not. Reading all three together beats trusting a single number.
Why Usable Capacity Trails the Label
This is where “false advertising” complaints usually come from. A rated 2280mAh describes delivery under a specific test condition — typically low current, room temperature, down to the cutoff voltage. A camera draws high-current pulses and shuts down once voltage dips past a threshold, so it never empties the cell. Usable energy commonly lands around 90 percent of the label. That is normal operation, not a defect.
A few things pull it lower still:
- Cold. Below about 32°F capacity drops clearly, and near 14°F you may get roughly half.
- High-current loads. Burst shooting and 4K recording sag voltage faster, so usable capacity trails low-current discharge.
- Cycle wear. Around 80 percent remains after 300 to 500 cycles, so two-year-old cells delivering less is expected.
Variables That Outweigh Capacity
| Variable | Impact | What to do |
|---|---|---|
| Body draw | Large — bodies differ substantially | Estimate per model; do not carry over habits from another camera |
| Video vs stills | Large — video generally draws more | Schedule video by the hour; consider external power |
| Framing method | Moderate — viewfinder beats an always-on screen | Cut unnecessary screen time and review |
| Wireless features | Moderate — Wi-Fi, Bluetooth and transfers add steady draw | Turn them off when idle |
| Temperature | Moderate to large — both extremes cost you | Inside pockets, rotate cells, avoid direct sun |
| Cell health | Moderate to large — aged cells sag under load | Check periodically; replace around two years |
| 5 percent capacity | Small — tens of frames | Decide on margin and budget |
The takeaway: shifting attention from “2280 or 2400” to “how many cells and how well maintained” improves your day far more.
Which One Should You Buy
- Choose 2280mAh if budget comes first, you need several cells, you finish days with charge left, or stills dominate.
- Choose 2400mAh if you regularly run cells empty, shoot a lot of video, want more per-cell headroom, or dislike frequent swaps.
- Mix them — put 2400mAh on your most demanding body, keep 2280mAh for daily and backup duty, and balance cost against experience.
Both share the same spec and swap freely. For naming differences, see TNP-FZ100 vs NP-FZ100.
Spotting Inflated Capacity Claims
- Check that both mAh and Wh are listed; they should reconcile, since Wh is roughly volts times amp-hours. A single number, especially an unusually high one, deserves skepticism.
- Check the rated voltage. The NP-FZ100 spec is 7.2V — anything else is not this battery.
- Look at build quality: printing seams, joint fit and contact finish are usually tidy on legitimate products.
- Check that warranty and return terms exist. Sellers who stand behind a product tend to publish conservative ratings.
- Log your own real-world results once you own it. Your own baseline beats any spec sheet.
FAQ
Is the 2400mAh version thicker or harder to fit?
No. Same physical standard, same dimensions and contacts, fully interchangeable. The extra capacity comes from improved cell energy density, not a bigger shell.
My tester reads a bit over 2200mAh on a 2280mAh cell. Normal?
That sits in the expected range. Real delivery depends on cutoff voltage, discharge current and temperature, and landing around 90 percent of the label is standard lithium behavior.
Do higher-capacity cells swell more often?
Swelling tracks cell quality, overcharge, deep discharge, heat and physical damage, not the capacity figure. Any sign of bulging or abnormal heat means stop using it immediately.
Can both capacities be used in one shoot?
Yes, same spec and interchangeable. Label them, and avoid rotating cells with very different wear levels, which makes charge management confusing.
Bottom Line
The 2280 versus 2400 question deserves a glance, not an argument. What actually determines whether a shoot runs smoothly is cell count, cell health and habits. Our NP-FZ100 at 2280mAh and around 16.4Wh is about $17.89 per cell, about $22.93 with a charger and about $36.74 for two with a charger. The TNP-FZ100 at 2400mAh and around 17.3Wh is about $19.66 per cell, about $24.70 with a charger and about $39.92 for two with a charger. Model-by-model specs are in our Sony mirrorless battery chart, and the genuine-versus-third-party trade-off at NP-FZ100 genuine vs third-party. Bulk orders of 100 or more go through our wholesale inquiry.