Power on location: batteries, power banks and power stations

A documentary shoot rarely stops because the story ran out. It stops because the last battery went flat at four in the afternoon, in a farmhouse with one free outlet, with a contributor who has already given you most of a day. Planning power on location is mostly arithmetic and habit, and it is one of the few parts of a shoot where a little care buys a lot of certainty.

This is how I would plan it for a small crew: list everything that draws power, count batteries per day, then choose between power banks, NP-F packs, a portable power station and, rarely, a generator. Flying and safety come last, and they are not optional.

How to power a film shoot on location: start with a list

Before packing anything, write down every device that needs power, how it is powered and how it recharges. The list is short for a two-person crew, and it still surprises people.

The last column is where shoots go wrong. Each line on it is a small, specific failure that shows up at the worst moment.

Count batteries per day

The sum is simple: hours the device is switched on, divided by hours one battery lasts, rounded up, plus one spare. Use powered-on time, not recording time. A camera on standby between takes, with the screen lit and stabilization running, is drawing power the whole time.

Hours per battery should come from your own log, on your own settings. Makers' figures are a starting point, but codec, screen brightness, stabilization and temperature all change the answer. Say your notes show a camera battery lasts about an hour and a half on your settings, and the camera will be on for seven hours. Seven divided by one and a half is 4.67, so round up to five and add a spare: six batteries.

Then check the night. If each battery takes about two hours to charge (look up your own charger), a single-slot charger needs twelve hours to refill six of them, which is longer than most shoot nights. A dual charger, or two chargers, solves it. Pack a power bar too, because hotel rooms and billets tend to have one outlet behind the bed.

Mark charged and flat batteries the same way every time: a strip of tape, or the cover turned one way for full and the other for empty. In cold weather, and a Canadian November counts, batteries give less, so carry the spares in an inside pocket rather than in the bag.

USB-C power for mic kits, phones and recorders

Most small sound kit now charges over USB-C, which makes a power bank the most useful power item in the bag. USB-C Power Delivery lets a charger and a device agree on a voltage, so the same bank can top up a phone, a wireless mic case and, if it is powerful enough, some laptops. A power bank for camera use is worth considering too: some cameras run or charge over USB-C, many only charge the battery when switched off, and the manual is the only reliable answer for your model.

A power bank's capacity in milliamp-hours is measured at the cell voltage, usually around 3.6 to 3.7 volts. Multiply milliamp-hours by that voltage and divide by 1,000 to get watt-hours, the figure airlines use and the one normally printed on the case. A 20,000 mAh bank works out to roughly 72 to 74 watt-hours at the cells, and less reaches your devices because conversion loses some on the way.

A word on method: I picked these from makers' documentation and published specifications, then looked for a long record on real shoots. They were not tested for this piece. The Anker 20,000 mAh power bank has a built-in USB-C cable, which is one less cable to forget. The DJI Mic Mini kit has two clip-on transmitters, one receiver and a charging case, and topping up the case from a bank at lunch is an easy habit to build. Carry a spare short cable as well; in my view a tired cable is the commonest fault in any USB-C setup. For more on the mic side, see our guide to lavalier and wireless microphones for documentary.

NP-F batteries for LED panels and monitors

NP-F is a battery shape Sony introduced for its camcorders, and it became an informal standard. Many small LED panels, field monitors and some recorders carry an NP-F plate, and third-party batteries in that shape are common. The sizes run F550, F750 and F970; a bigger number means more capacity and more weight.

LED panels draw the most at full output and less when dimmed, so a panel used as soft fill at half power lasts noticeably longer than the same panel used as a key. Mount batteries securely, because an NP-F970 hanging off the back of a light on a tall stand changes how that stand behaves. If you are still choosing lights, our piece on LED panels, COB lights and softboxes for interview lighting covers the options.

The Neewer NP-F970 set comes as two large NP-F style batteries with a charger. Paired with a small bi-colour panel kit, they give you an interview light setup for a room with no free outlet. Confirm in the manual that your panels take NP-F batteries before you buy for them; many small bi-colour panels do, but check yours.

Portable power stations for filmmaking

A portable power station is a large lithium battery with an inverter for mains-style AC sockets, plus USB-C and DC outputs. Two numbers matter. Capacity, in watt-hours, says how long it can run things. Output, in watts, says how much it can run at once; plug in more than that and it shuts off.

For a rough runtime, divide the capacity by the load and then expect noticeably less, because the inverter that makes AC power uses some of the energy. A light drawing 100 watts on a 1,000 watt-hour station will run for something under ten hours. Add a laptop and two battery chargers and the sum changes quickly, so write it down. Check that the inverter is pure sine wave, which some chargers and audio gear prefer.

Where a power station is genuinely the pick: an interview in a cabin, a boat, a field or a church hall whose circuits are already full; a vehicle base where camera batteries and the laptop recharge between locations; any place where a generator would ruin the sound. For a two-light interview somewhere without outlets, an EcoFlow power station, or one of BLUETTI's in the same size class, is the tool I would budget for; size either one to the lights' combined wattage. Where it is not the pick: if you are flying, if you are carrying everything on foot, or if the day only needs phones and mic kits, where a power bank does the job.

Power stations recharge from the wall overnight, from a car outlet while driving, or slowly from solar panels. Plan the overnight recharge the same way you plan camera batteries.

Generators and noise

Generators make noise and fumes, and on a documentary both are a problem. Inverter generators are quieter than open-frame models and give cleaner power for electronics, but quieter is not silent. If you need one, put it as far from the set as your cable allows, behind a building or vehicle, and downwind.

Carbon monoxide is the serious risk. Never run a generator indoors, in a garage, in a tent, or near windows, doors or vents. Let it cool before refuelling, store fuel away from it, and check whether the location or the municipality needs a permit or has noise bylaws. For most small documentary crews a power station replaces the generator entirely, and your sound recordist will thank you.

Flying with lithium batteries

Spare lithium batteries, including camera batteries, NP-F packs and power banks, go in carry-on bags, not checked luggage. Protect the terminals with caps, the original packaging or a separate pouch for each battery. Airlines set limits by watt-hours per battery, larger batteries need the airline's approval, and some are not allowed on passenger flights at all. The watt-hour rating printed on each battery is what airport security and the airline will look for.

Most portable power stations are far beyond what any passenger airline accepts. If your shoot needs one at the other end, rent or buy it there. The rules vary between airlines and change over time, so check your airline's own page, and the national regulator's, the week you fly.

Safety on location

1. Know the circuit. In Canadian homes most outlets are on 15-amp, 120-volt circuits, about 1,800 watts in theory and less for loads that run for hours. A kettle, a space heater and two lights on one circuit will trip the breaker. Ask the location contact where the panel is before you plug in.
2. Do not daisy-chain power bars, and do not run cables under rugs, where they can heat up unseen.
3. Tape down or cover every cable that crosses a walkway, especially where contributors, children or older people walk.
4. Keep connections off wet ground. Outside, use outdoor-rated cords and ground fault protection.
5. Retire any battery that is swollen, cracked or hot to the touch. Charge on a hard surface, not on a bed or sofa, and not unattended overnight if you can avoid it.
6. Let a cold battery warm to room temperature before you charge it, and never leave batteries on a car dashboard in the sun.

Put the power plan on the call sheet with everything else: who packs the chargers, where they plug in at night, and who checks the tape on the batteries in the morning. If cards and drives travel in the same bag, our guide to storage for a documentary shoot covers that half of the overnight routine.

Questions

How do I power a film shoot with no outlets?

List every device, count batteries for the day with a spare for each, and carry a power bank for USB-C kit. If lights or a laptop need mains-style power, a portable power station sized to their combined wattage is the quiet option; a generator is the last resort, placed well away from the set.

Can I use a power bank for my camera?

Sometimes. Some cameras run or charge over USB-C, many only charge the battery while switched off, and some need a specific power level. Check the camera manual, then use a Power Delivery bank and a good short cable.

How many camera batteries do I need for a shoot day?

Divide the hours the camera will be switched on by the hours one battery lasts on your settings, round up, and add one. Then check your charger can refill them overnight.

Can I take camera batteries and power banks on a plane?

Generally yes, in carry-on only, with the terminals protected. Limits are set by watt-hours per battery and vary by airline, and larger batteries need approval or are refused. Check your airline before you pack.