Questions about the NP-FZ100 tend to cluster into five groups: will it work in my camera, what is that message on the screen, what do I do about a swollen pack, how should I charge and store it, and how many can I take on a plane. Each group is answered below, with a few extras at the end. If what you need is a camera-by-camera list, the full NP-FZ100 compatibility list is the right page; for run-time figures, head to the battery life database.
Compatibility: which bodies take the NP-FZ100
Which Sony cameras run on the NP-FZ100?
Mostly these: A7 III, A7R III, A7R IV, A7R V, A7 IV, A7S III, A9, A9 II, A9 III, A1, A6600, A6700, A7C, A7C II, A7CR, FX3, FX30 and ZV-E1.
Will it fit the A6400?
No. The A6400, A6500, A6300, A6000 and the A7, A7 II, A7R II and A7S II all use the NP-FW50, and the RX100 series uses NP-BX1. This is the single most common mix-up, so trust the label printed inside your battery compartment.
Can I move a battery between bodies?
Yes. Every compatible body above shares the same pack, which is why multi-camera shooters stock one type and stop thinking about it.
Warnings and errors: which are normal and which need attention
“Remaining charge may not be displayed accurately” — can I keep shooting?
Yes. This is a communication difference between body and pack. The percentage readout is simply less precise than with an OEM cell; it may jump or sit on one number for a while. Switch to a bar or voltage display, or time your changes around your usual frame count.
“Cannot recognise” or “cannot use” — what now?
This one is a genuine fault, not a display note. Work through it in order: confirm the pack really is NP-FZ100; check both sets of contacts for dirt or oxidation and wipe them dry; swap in another battery to see whether the fault follows the cell or the body; and if the pack just came in from the cold, let it reach room temperature first.
Why does the grip not see the battery?
Check that it went in the right way round and is fully seated before anything else, then look at the grip contacts. Two cells with very different state of health can also confuse things, so pair batteries of similar condition where you can.
Swelling and safety: what to do if something looks wrong
Can I still use a swollen battery?
No. Take a swollen pack out of service immediately. Do not charge or discharge it further, do not puncture or burn it, and hand it over at a proper battery or hazardous waste facility. Swelling means gas has formed inside the cell, and there is no safe way to keep running it.
Is heat during charging normal?
Some warmth is fine. If the pack is hot to the touch, smells odd or has deformed, disconnect the charger, move it somewhere open and uncluttered and follow the recycling route. Treat every safety step here as a recommendation to take seriously rather than an optional precaution.
My run time dropped sharply — is the battery dead?
Not necessarily. Lithium cells hold roughly 80 percent of their capacity after 300 to 500 cycles, so a slight decline after a year and a clear one around two years is ordinary ageing. Number your cells, log their start dates and replace them in batches.
Charging and storage: getting the most life out of them
Should I drain it fully before recharging?
No — top up whenever it suits. Lithium cells have no memory effect, and deep discharge puts more strain on them. Avoid leaving a pack sitting at zero or pinned at 100 percent.
Do I need to pull it the moment the light changes?
Once the indicator shows a full charge, go ahead and take it off. Leaving packs parked on the charger for long stretches does nothing useful, particularly somewhere unattended.
How should I store batteries I will not use for a while?
Around 40 to 60 percent charge, somewhere cool and dry near 15–25°C (59–77°F), topped up every three months. Not in a sunlit car, and not somewhere damp.
Run time collapses in the cold. Anything I can do?
Capacity falls noticeably below freezing and may be close to halved at around −10°C (14°F). What helps: keep spares in an inside pocket, rotate cells as you go, and let a spent one warm up in your pocket before you decide it is finished — that often brings back usable charge. In winter, carry one or two more than usual.
Air travel: how many, and can they go in checked bags
Can I fly with NP-FZ100 batteries?
Yes. At roughly 16.4Wh per cell they sit well under the 100Wh line, so they are not treated as large lithium batteries and do not require airline approval — but spares must go in your carry-on, never in checked luggage.
What protection do they need?
Insulate the terminals against short circuits. Original packaging, the supplied cap or a strip of tape over the contacts all satisfy this. A pack installed in a camera body is treated differently, but protecting its contacts is a sensible habit anyway.
Is there a limit on how many?
Some carriers cap the number of spares per passenger, commonly around 20. Confirm against your airline’s own policy before departure, especially for a crew travelling together with several bodies.
Buying: a few frequent questions
Are third-party batteries worth it?
Compatible cells are a legal alternative. An OEM Sony pack typically runs $70 and up, while YO cells here are $17.89 each, $22.93 with a charger and $36.74 for two cells plus a charger. The same budget stretches considerably further, and when you need power all day, quantity usually counts for more than the label. Details in the third-party NP-FZ100 buying guide.
How much difference is there between 2280mAh and 2400mAh?
About 5 percent in energy terms: roughly 16.4Wh against 17.3Wh. In the field that reads as a few extra frames per cell and one fewer swap. If you mostly work indoors or on sticks, external power makes more of a difference; if you shoot handheld on the move, an extra battery is usually the better spend.
Can I mix different brands?
Yes, but manage them in batches and keep them numbered. Try not to pair cells whose state of health differs widely, since that makes the batch harder to judge as it ages.
Top up your power supply
For one more spare: the YO NP-FZ100, 2280mAh and roughly 16.4Wh, at $17.89 each, $22.93 with a charger and $36.74 for the two-battery kit. Prefer more capacity per cell: the TNP-FZ100, 2400mAh and roughly 17.3Wh, $19.66 each and $39.92 for two plus charger. Studios, rental houses and resellers should use the wholesale enquiry page, with quotes from 100 units up.