Short answer: charge the NP-F960 on a dedicated cradle. At 8.4V / 0.8A a 38.9Wh pack fills in roughly six to seven hours. Most camcorders that take NP-F packs do not charge the battery in the body. For long storage, keep 40–60 percent and top up every three months. If the case swells, deforms or the contacts get hot, stop using it. Every time below is an estimate derived from charger output and 85 percent conversion efficiency, not a measurement, and real charging adds ten to twenty minutes of constant-voltage taper.
Single or dual charger: where the current goes
A single-slot charger has one bay and can give the whole output to that pack. The circuit is simple and the price is low. The drawback is one battery at a time, so two packs queue up.
A dual charger has two bays and looks easier, but read the label: is it 1A per bay or 1A total? A shared 1A model splits the current between two packs, so charging both takes close to twice as long as one. It saves plugging, not time. Only independent channels deliver the real doubling.
Choose by pack count. With two packs in rotation, a single-slot charger is enough because one is usually on the camera. With three or more, a dual saves handling, provided the channels are independent.
Charging time: the formula and a table
The estimate is energy ÷ (charge voltage × charge current × efficiency). NP-F is a two-cell series pack, so chargers output 8.4V, and efficiency is taken as 0.85. At 0.8A: 8.4 × 0.8 = 6.72W, times 0.85 gives about 5.7W, and 38.9 ÷ 5.7 ≈ 6.8 hours.
| Method | Approximate time (estimate) | Where it fits |
|---|---|---|
| Single cradle, 8.4V / 0.6A | about 9 hours | Overnight, ready for the next day |
| Single cradle, 8.4V / 1A | about 5.5 hours | A fast top-up during the day |
| Dual cradle, independent 8.4V / 1A | about 5.5 hours each, slightly longer for two | Charging the kit before a shoot |
| Camera body (where supported) | usually slower, see the manual | Emergencies only |
| 12V car supply to 8.4V | close to a single cradle, varies with vehicle voltage | Topping up on the road |
The table leaves out the constant-voltage taper. Once the pack reaches 8.4V the current falls on its own, and this last stage is slow, typically another ten to twenty minutes. Plan a 1A cradle at five and a half to six hours rather than exactly 5.5.
Can the camera body charge it
Most camcorders that use NP-F packs do not charge the battery internally. The DC IN socket powers the body, so an adapter lets you shoot for long sessions, but the pack in the bay is not being filled. Charging means taking it out and using a cradle.
A few bodies do support in-body charging. It is usually slower than a cradle, the camera is largely unusable while it runs, and the body gets warmer. Whether yours qualifies is a question for the power section of the manual, not for guesswork.
Storage, ageing and when to retire a pack
Before storing, bring the pack to 40–60 percent. A full pack sits at high voltage for months and ages faster; a pack drained until cutoff may self-discharge below the protection threshold and refuse to charge again.
Top it up every three months, to about half, not full. Keep it cool and dry, away from a sun-baked car and away from radiators. Warmer storage speeds both self-discharge and ageing.
On cycle life, only the direction is honest: capacity declines gradually with charge and discharge cycles, which is normal for lithium cells, and no service life can be guaranteed. A large pack delivers more energy per shoot, so it sees fewer cycles for the same workload, though total energy throughput is no smaller than with a small pack.
The retirement signs are worth memorising: a swollen case, deformed corners, a pack that rocks when laid flat, contacts or surfaces that get noticeably hot, or any smell. Any one of them means stop, do not recharge, do not mount it. Continuing brings no benefit, only risk.
Two packs is the practical setup: one on the camera, one on the charger. Specifications are on the NP-F960 product page, and other packs sit under Sony NP-F960 series.
FAQ
Can I leave it charging overnight?
A cradle terminates at full, so a night on the charger usually will not overcharge, but the pack sits warm for hours. Unplug when you can, especially in summer.
Does a new pack need a 12-hour first charge?
No. Lithium packs are activated at the factory. A normal full charge is enough, and a long trickle brings nothing.
Can I use one pack while charging the other?
Yes, and that is the most practical rhythm. Keep the charger ventilated and never put a charging pack inside a bag.
How often should a stored pack be topped up?
Every three months is a sensible interval. Stop at about half; there is no need to store it full.