For this comparison we took three NP-FZ100 cells from the same general price band — call them samples A, B and C, with no brands named — and ran them through one procedure at room temperature, measuring usable capacity, approximate DC resistance and temperature rise during charging. In our lab testing, all three landed in the neighborhood of their rated capacity, separated by only a few percentage points. Resistance differed more, and tracked with how each behaved under load. Charging temperature rise stayed in the “slightly warm” band for all three, with no meaningful spread between them.
Everything here is presented as a range. The sample count is small, individual measurements drift, and the intent is to show the method and the scale of the differences — not to certify one specific product.
Method and conditions
- Ambient temperature: a normal indoor range, no direct airflow across the samples, logged throughout.
- Charging: one known-good charger for all samples, then a rest period after the indicator turned green before discharge began.
- Discharge: constant-current electronic load, with the cutoff set to the usual lower limit for a 7.2V nominal pack; three runs per sample, reported as a range.
- Resistance: approximate DC method (voltage drop across load ÷ current), not a four-wire AC measurement — good for ranking, not for absolute values.
- Temperature: measured at the same point on the shell, recorded as the difference between surface and ambient at the end of charging.
- Samples: three cells bought at random, unopened, with no pre-screening.
The value of this setup is comparison under identical conditions. Absolute numbers describe these samples only; the spread between them is what carries over.
Results and what each one means
| Item | Sample A | Sample B | Sample C | Our read |
|---|---|---|---|---|
| Rated capacity | Around 2280mAh | Around 2280mAh | 2400mAh class | C is rated higher |
| Usable capacity measured | Roughly 2150–2250mAh | Roughly 2100–2210mAh | Roughly 2250–2350mAh | All above 90% of rating |
| Capacity achieved | About 95%–98% | About 93%–97% | About 95%–98% | A few points apart |
| Approx. DC resistance | Low-to-mid range | Low-to-mid range | Low-to-mid range | B ran slightly higher |
| Shell temperature rise | Slightly warm | Slightly warm | Slightly warm | Comparable across all three |
| Consistency across repeats | Tight | Looser | Tight | Matches the resistance result |
Condensed into one line: capacity is not where these cells separate — consistency is. The gap in usable capacity is much smaller than the gap in how they behave under heavy load.
Capacity: why the measurement always lands under the label
Start by clearing up a common misreading: a 2280mAh rating does not promise 2280mAh delivered. The label is a typical value under a specific temperature, discharge rate and cutoff. In a camera:
- Discharge rates are higher: the body pulls far more current than a gentle bench discharge, so usable capacity drops.
- Cutoff arrives earlier: the camera declares empty while there is still charge left, to keep itself running properly.
- Temperature is not ideal: below room temperature, usable capacity falls noticeably.
In our testing, achieving around 90% or more of the rated figure usually indicates an honest label. Coming in well under roughly 80% is a reasonable trigger to suspect the rating. The check is described in how to spot inflated capacity ratings.
Resistance: the number behind “it still had two bars”
A cell with higher resistance behaves fine at low current, then sags the moment you ask for real power — fast bursts, repeated flash recycling, starting a 4K clip. The body reads the sag as empty and sometimes shuts down. That is why some cells stop working while the gauge still shows charge.
- When new: our three samples sat close together in the low-to-mid range.
- After cycling: how fast resistance climbs is the real separator, and that takes long-term use or accelerated cycling to see.
- What you can feel instead: at the same indicated level, whether burst slows down and flash recycling drags.
For weddings, sports and anything you cannot pause, weight those load behaviors — or the feel-based equivalents — more heavily than the capacity number on the label.
Temperature: what it means that all three were similar
Heat during charge and discharge is normal physics. In our testing, all three samples finished a standard charge only slightly warm to the touch, with none hot. Points worth keeping:
- Rise tracks charge current: a faster charging setup means noticeably more heat.
- Heat accelerates aging: cells that live hot lose capacity sooner.
- Don’t charge in a sealed space: a padded bag divider or a sunlit car interior both trap heat.
- Hot means stop: slightly warm is fine, hot is a signal to investigate.
The broader safety picture is laid out in our guide to third-party camera battery safety.
Turning the comparison into a buying decision
- Don’t agonize over a few dozen mAh: the felt difference between 2280mAh and 2400mAh is small — see 2280mAh versus 2400mAh.
- Favor clear warranty terms and traceable labeling: what you cannot see inside the pack has to be backed by someone taking responsibility. See the NP-FZ100 warranty page.
- Buy several from one batch: a single batch tends to be more consistent and makes rotation by number simple.
- Watch what you can verify yourself: how many frames you actually get from a full charge, and whether burst slows — more useful than any spec sheet.
- On a tight budget, buy quantity: an extra cell usually pays off more than a slightly higher rating.
The structural view — cells, protection board, communication circuit — is in inside a third-party NP-FZ100.
FAQ
Why not publish exact milliamp readings?
Single measurements drift with environment and equipment, and over-precise figures mislead more than they inform. Ranges represent the real scale of the differences and keep the data honest.
Why only three samples?
Time and sample availability set the limit. Three are enough to answer “how much do cells in this price band differ,” but not enough to draw conclusions about any specific brand.
Does higher capacity achieved mean a better cell?
Not on its own. Read capacity alongside resistance, retention after cycling and warranty terms. Capacity alone hides how a cell behaves under load.
Can I repeat any of this at home?
Capacity and runtime can be approximated by counting frames through a fixed shooting routine. Resistance needs a proper load; for most people, feel-based observation is enough, and buying gear purely to measure is not worth it.
Our NP-FZ100 compatible battery is rated 2280mAh / 7.2V / around 16.4Wh, at around $17.89 per cell, around $22.93 for one cell with a charger and around $36.74 for two cells with a charger. For more capacity, the TNP-FZ100 (2400mAh / around 17.3Wh) runs around $39.92 for the two-cell kit. Reviewers, purchasing teams and studios wanting to run their own sample comparisons are welcome to use the wholesale inquiry page for volume pricing and same-batch samples.