Short answer: the Z6 II, Z7 II and Z8 all ship with an EN-EL15c. Its 2280mAh is only about 20% more than the older version, so the real threshold is communication and charge management: only the EN-EL15b and EN-EL15c can enable in-body USB charging and USB PD power, and only they report charge percentage and battery-age information in full. An older EN-EL15 will not trigger an error in these bodies, but you lose those functions and you meet a low-charge warning sooner under heavy load.
What the three bodies actually require
Start with the differences between them. They share a bay specification but not the same power demand: the Z8 has little scope for saving power beyond its mechanical shutter, and 8K plus high-frame-rate 4K are sustained high-current loads. The Z6 II and Z7 II are gentler, though dual EXPEED 6 processors and five-axis stabilisation still run constantly.
| Body | Supplied pack | Accepted packs | In-body USB charging | USB PD shooting |
|---|---|---|---|---|
| Z6 II | EN-EL15c | EN-EL15 / 15a / 15b / 15c | Requires 15b or 15c | Requires 15b or 15c |
| Z7 II | EN-EL15c | EN-EL15 / 15a / 15b / 15c | Requires 15b or 15c | Requires 15b or 15c |
| Z8 | EN-EL15c | EN-EL15 / 15a / 15b / 15c | Requires 15b or 15c | Requires 15b or 15c |
Accepted and fully usable are two different things. Nikon’s compatibility notes are explicit that older packs can be used in the body but that some functions are limited. That detail usually appears as a footnote in the manual, which is easy to miss.
Three concrete limits on older packs
1. About 20% less capacity, and heavy loads widen the gap
1900mAh against 2280mAh is 380mAh on paper. In a DSLR that might only mean a hundred-odd fewer frames, but in a Z8, with 8K recording, burst buffer writes and stabilisation all working at once, the current is high and rising internal resistance trims usable capacity further. An old pack usually performs worse than the rated ratio suggests.
2. In-body USB charging simply stops working
This is the most consequential limit. The Z6 II, Z7 II and Z8 all accept a USB-C supply to charge the pack inside the body and to keep shooting while plugged in. That depends on charge-management circuitry built into the pack, which the first-generation EN-EL15 and the EN-EL15a do not have. Plug in and the camera merely switches to external supply; the charge level does not rise.
For timelapse, streaming or studio work at a fixed position, in-body charging defines two entirely different workflows: with it, one pack can run all day; without it, you swap packs mid-session or hang a dummy battery off the body.
3. Battery data and battery-age display are incomplete
Z-series bodies offer a battery-age display showing relative health. That figure comes from a recording chip inside the pack, which older packs often cannot be read for, or which reports distorted values. Charge percentages that jump also occur, and in cold conditions a fall from 30% straight to shutdown is more likely.
Why the Z8 is more sensitive
The Z8 sits at the higher end of Nikon’s mirrorless power draw: a square body, damping design beyond the mechanical front curtain, a bright EVF and 8K recording all point to sustained high current. Its official CIPA figure is in the low three hundreds, and in real use two or three hundred frames plus some video will usually exhaust a single EN-EL15c before the day ends.
More telling is the derating behaviour. Once charge falls below a certain point, or internal resistance causes voltage sag, the body actively limits some functions — lower burst rate, capped 8K clip length. It never says “because the pack is weak”; it just feels as though the camera has suddenly slowed down. With old packs, that confusion comes up more often.
Planning a sensible spare kit
- Run an EN-EL15c in the main body, original or a highly consistent third party. Z8 owners in particular should not economise here, since a mismatched protocol produces an outright “this battery cannot be used” message. When choosing a third party, look for a maker that has adapted to the Z8 and Z6 III; brands such as YO that publish a compatibility list are easier to buy from.
- One spare at minimum, two on a shooting day. For light use a Z6 II or Z7 II is fine with one plus one; a Z8 is better with two spares.
- Add a 30W-plus USB PD power bank. Plugged into the body during a break, it adds a meaningful amount in half an hour and saves swapping packs.
- Manage grip pairs together. On an MB-N11 or MB-N12, use packs of the same model and batch so the weaker one does not trigger an early warning for the pair.
If you tend to buy three or four packs at a time, standardising on the EN-EL15c is the simplest policy: it works in old DSLRs, is fully featured in new mirrorless bodies, and mixing does not cause problems. For the full picture across the four generations, see the EN-EL15 family guide. If you travel often, confirm the cabin limits in advance — the rules are set out in whether camera batteries can fly.
FAQ
Can a Z6 II use an EN-EL15a?
It fits and it works, and shooting functions are unaffected, but in-body USB charging and USB PD shooting stop working and the charge reading may be inaccurate. Acceptable for occasional emergency use; as a main pack, switch to the b or c version.
Is an EN-EL15b enough for a Z8?
Functionally yes — USB charging and power both work — it simply holds about 20% less than the c version. If the budget allows, the c version is the better choice for a Z8, with the b version kept as a spare.
Will a Z8 reject a third-party EN-EL15c?
It can. The Z8 validates packs strictly, and some third-party products that have not been adapted trigger the “this battery cannot be used” message. Choose one that explicitly states support for the Z8 and Z6 III, and test it in the body as soon as it arrives.
What can I do about poor runtime in the cold?
Falling discharge capability below freezing is physics, not a fault. Keep spares against your body, rotate them, and charge partly returns once they are back at room temperature. The approach in this minus 10°C battery test is worth reading; the method is brand-neutral.