Direct answer: in our tests, an NP-FZ100 keeps about 92%–96% of its usable capacity after 100 full cycles. By 300 cycles it sits near the mid-80s, and somewhere between 300 and 500 cycles you land around 80%, the point most of the industry treats as end-of-life. The first hundred cycles cost you less than most people assume. The moment a battery starts feeling tired usually arrives somewhere past two or three hundred. Here’s how one cycle is actually counted, where the retention figures come from, and which habits bend the curve downward early. For a calendar-based view instead of a cycle-based one, compare against a year of real-world capacity loss.
First: what counts as “one cycle”
Plenty of people count one trip to the charger as one cycle. That inflates wear dramatically. A cycle means the accumulated discharge equals the rated capacity:
- Shoot down to 50% today, charge it, then use another 50% tomorrow — together that’s one cycle, not two.
- Run from 100% to auto-shutdown and recharge: that’s one full cycle.
- If you habitually top up after using 20%, it takes five such sessions to add up to one cycle.
By that math a casual shooter might accumulate twenty or thirty cycles a year, while a wedding shooter or video team can easily clear a hundred. Same battery, very different lifespan.
Retention by cycle count
The table below reflects measurements taken under fixed conditions — roughly 25°C, constant-current discharge, multiple samples reported as a range. We don’t publish single-digit precision because it wouldn’t survive a repeat run.
| Cycles | Capacity retained (range) | What it means in practice | Recommendation |
|---|---|---|---|
| 0 (new) | About 100% | Nominal 2280mAh / about 16.4Wh | Log your starting runtime as a baseline |
| 50 | 96%–99% | Barely noticeable | Carry on |
| 100 | 92%–96% | Slightly tight at the end of a day | Start thinking about a second pack |
| 200 | 88%–93% | Obvious in video and burst work | Grow the rotation to three packs |
| 300 | 82%–88% | One pack no longer covers half a day | Put replacement on the calendar |
| 500 | Around 80% or lower | Short runtime, rising internal resistance | Replace |
One important distinction: the capacity percentage is not the same as the frame-count percentage. Runtime is capacity divided by how much power the body draws, and rising internal resistance makes the camera cut out earlier under heavy load. Real-world performance tends to fall off faster than the number suggests.
Our test protocol
- Environment: discharge runs at room temperature, about 25°C, so temperature doesn’t contaminate the result.
- Load: constant current to cutoff voltage, recording total charge delivered, cross-checked against actual shooting.
- Charging: the same charger specification every time, packs pulled only after the indicator flips, so no fake losses from a partial charge.
- Samples: several packs from one batch tracked in parallel, reported as ranges. A single outlier is never a finding.
- Reporting: ranges and “around” only. Cycle-life numbers quoted to the last digit aren’t repeatable in the real world.
Habits that bend the curve early
Leaving it at 100%
A pack sitting full in a bag or parked on the charger spends its life at high voltage, and that ages it faster. If a battery will be idle for more than a week, bring it to roughly 40%–60% before you put it away.
Heat
Hot cars in summer, sunny windowsills, or a battery pressed against a warm body for hours all speed up the decline. Heat frequently does more damage than extra cycles do.
Habitually hitting 0%
Shooting until the camera quits is a deep discharge, and it’s hard on the cell. Shallow, frequent top-ups are kinder.
Sustained high current
Fast bursts and high-bitrate 4K keep the cell dumping current and running warm. Rotate packs in those situations so each one gets a chance to cool.
Estimating your own cycle count
Bodies don’t report cycles directly, so here are four indirect routes:
- Work from frame count. If a pack covers roughly 500–700 frames per charge (CIPA-range), then 50,000 frames implies something close to a hundred cycles.
- Work from charging habits. Someone who recharges at the halfway point may need more than two years to reach 200 cycles.
- Watch the feel. Same body, same settings, twenty percent fewer frames than a new pack? You’re probably nearing the 300-cycle zone.
- Measure it. A charger with capacity readout or an inline coulomb meter gives the straightest answer.
What actually extends life
- Top up opportunistically. Avoid deep discharges to 0%, and avoid sitting at 100% for weeks.
- For long storage, leave it at 40%–60%, cool and dry at 15–25°C, and top it up every three months.
- Rotate several packs so no single battery carries every heavy job.
- Slight warmth while charging is normal. Hot to the touch means stop, and check both the battery and the charger.
- Any swelling means retirement for that pack and a trip to a proper recycling stream. No puncturing, no burning.
The fuller checklist sits in five habits that extend NP-FZ100 life.
FAQ
Is a pack worthless after 100 cycles?
Far from it. It still holds nine-tenths or more of its capacity; you just want a spare on hand for heavy days. Replacement territory starts nearer 300 cycles, or once runtime drops toward 70%.
Do third-party cells lose a lot of cycle life versus Sony’s?
In our observations, under matched use and storage, the two curve shapes track each other. Individual outcomes depend far more on cell batch and habit than on branding.
Does fast charging shorten cycle life?
Current within the pack’s specification isn’t a major factor. Heat and permanent full-charge states are. If a pack gets genuinely hot while charging, stop and investigate.
Can I keep using a battery past its rated cycles?
Yes. It simply holds less and sags more under load. Demote it to backup duty or low-draw work like time-lapse on a locked-off body, and give the demanding jobs to healthier packs.
Bottom line and buying notes
Three numbers are enough: about 92%–96% at 100 cycles, roughly the mid-80s at 300, around 80% between 300 and 500. Charging shallower and storing cooler will buy you more life than agonizing over the label will. When you do need more capacity, YO’s NP-FZ100 compatible battery (2280mAh / 7.2V / about 16.4Wh) is around $17.89, the one-battery-one-charger kit about $22.93, and the two-battery kit about $36.74. Want a bit more headroom? The TNP-FZ100 (2400mAh / about 17.3Wh) is around $19.66, or about $39.92 for two batteries with a charger. Sony’s original pack runs $70 and up. The wider cost-versus-life trade-off is covered in Sony original vs third-party NP-FZ100 compared. Studios, rental houses, and resellers ordering 100 units or more should use the wholesale inquiry page for a quote.